diff --git a/Libraries/SPTarkov.Server.Core/Controllers/InventoryController.cs b/Libraries/SPTarkov.Server.Core/Controllers/InventoryController.cs
index 0571cc8a..8d22f7e6 100644
--- a/Libraries/SPTarkov.Server.Core/Controllers/InventoryController.cs
+++ b/Libraries/SPTarkov.Server.Core/Controllers/InventoryController.cs
@@ -179,7 +179,7 @@ public class InventoryController(
     /// <param name="pmcData">Players PMC profile</param>
     /// <param name="request"></param>
     /// <param name="sessionId">Session/Player id</param>
-    public void SetFavoriteItem(PmcData pmcData, SetFavoriteItems request, string sessionId)
+    public void SetFavoriteItem(PmcData pmcData, SetFavoriteItems request, MongoId sessionId)
     {
         // The client sends the full list of favorite items, so clear the current favorites
         pmcData.Inventory.FavoriteItems = [];
diff --git a/Libraries/SPTarkov.Server.Core/Controllers/RagfairController.cs b/Libraries/SPTarkov.Server.Core/Controllers/RagfairController.cs
index a1838685..05835aba 100644
--- a/Libraries/SPTarkov.Server.Core/Controllers/RagfairController.cs
+++ b/Libraries/SPTarkov.Server.Core/Controllers/RagfairController.cs
@@ -989,7 +989,7 @@ public class RagfairController(
     /// <param name="sellInOnePiece">Is this a pack offer</param>
     /// <returns>RagfairOffer</returns>
     protected RagfairOffer CreatePlayerOffer(
-        string sessionId,
+        MongoId sessionId,
         List<Requirement> requirements,
         List<Item> items,
         bool sellInOnePiece
@@ -1272,7 +1272,7 @@ public class RagfairController(
         return ragfairPriceService.GetAllStaticPrices();
     }
 
-    public RagfairOffer? GetOfferByInternalId(string sessionId, GetRagfairOfferByIdRequest request)
+    public RagfairOffer? GetOfferByInternalId(MongoId sessionId, GetRagfairOfferByIdRequest request)
     {
         var offers = ragfairOfferService.GetOffers();
         var offerToReturn = offers.FirstOrDefault(offer => offer.InternalId == request.Id);
diff --git a/Libraries/SPTarkov.Server.Core/Controllers/RepeatableQuestController.cs b/Libraries/SPTarkov.Server.Core/Controllers/RepeatableQuestController.cs
index 48bf4ca1..cf06c5cd 100644
--- a/Libraries/SPTarkov.Server.Core/Controllers/RepeatableQuestController.cs
+++ b/Libraries/SPTarkov.Server.Core/Controllers/RepeatableQuestController.cs
@@ -422,7 +422,7 @@ public class RepeatableQuestController(
     public RepeatableQuest? PickAndGenerateRandomRepeatableQuest(
         MongoId sessionId,
         int pmcLevel,
-        Dictionary<string, TraderInfo> pmcTraderInfo,
+        Dictionary<MongoId, TraderInfo> pmcTraderInfo,
         QuestTypePool questTypePool,
         RepeatableQuestConfig repeatableConfig
     )
diff --git a/Libraries/SPTarkov.Server.Core/Extensions/CurrencyTypeExtensions.cs b/Libraries/SPTarkov.Server.Core/Extensions/CurrencyTypeExtensions.cs
index a1fa64ea..b4233c3d 100644
--- a/Libraries/SPTarkov.Server.Core/Extensions/CurrencyTypeExtensions.cs
+++ b/Libraries/SPTarkov.Server.Core/Extensions/CurrencyTypeExtensions.cs
@@ -1,4 +1,5 @@
-using SPTarkov.Server.Core.Models.Enums;
+using SPTarkov.Server.Core.Models.Common;
+using SPTarkov.Server.Core.Models.Enums;
 
 namespace SPTarkov.Server.Core.Extensions
 {
@@ -9,7 +10,7 @@ namespace SPTarkov.Server.Core.Extensions
         /// </summary>
         /// <param name="currency"></param>
         /// <returns>Tpl of currency</returns>
-        public static string GetCurrencyTpl(this CurrencyType currency)
+        public static MongoId GetCurrencyTpl(this CurrencyType currency)
         {
             return currency switch
             {
diff --git a/Libraries/SPTarkov.Server.Core/Extensions/ItemEventRouterResponseExtensions.cs b/Libraries/SPTarkov.Server.Core/Extensions/ItemEventRouterResponseExtensions.cs
index 6654f063..83bc1d41 100644
--- a/Libraries/SPTarkov.Server.Core/Extensions/ItemEventRouterResponseExtensions.cs
+++ b/Libraries/SPTarkov.Server.Core/Extensions/ItemEventRouterResponseExtensions.cs
@@ -1,4 +1,5 @@
-using SPTarkov.Server.Core.Models.Eft.Common.Tables;
+using SPTarkov.Server.Core.Models.Common;
+using SPTarkov.Server.Core.Models.Eft.Common.Tables;
 using SPTarkov.Server.Core.Models.Eft.ItemEvent;
 
 namespace SPTarkov.Server.Core.Extensions
@@ -13,10 +14,11 @@ namespace SPTarkov.Server.Core.Extensions
         /// <param name="item">Item that was adjusted</param>
         public static void AddItemStackSizeChangeIntoEventResponse(
             this ItemEventRouterResponse output,
-            string sessionId,
+            MongoId sessionId,
             Item item
         )
         {
+            // TODO: replace with something safer like TryGet
             output
                 .ProfileChanges[sessionId]
                 .Items.ChangedItems.Add(
diff --git a/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs b/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
index b9291d5f..6778458c 100644
--- a/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
+++ b/Libraries/SPTarkov.Server.Core/Generators/RagfairOfferGenerator.cs
@@ -60,7 +60,7 @@ public class RagfairOfferGenerator(
     /// <param name="sellInOnePiece">Flags sellInOnePiece to be true</param>
     /// <returns>RagfairOffer</returns>
     public RagfairOffer CreateAndAddFleaOffer(
-        string userId,
+        MongoId userId,
         long time,
         List<Item> items,
         List<BarterScheme> barterScheme,
@@ -95,7 +95,7 @@ public class RagfairOfferGenerator(
     /// <param name="isPackOffer">Is offer being created flagged as a pack</param>
     /// <returns>RagfairOffer</returns>
     protected RagfairOffer CreateOffer(
-        string userId,
+        MongoId userId,
         long time,
         List<Item> items,
         List<BarterScheme> barterScheme,
@@ -177,7 +177,7 @@ public class RagfairOfferGenerator(
     /// <param name="userId">User creating the offer</param>
     /// <param name="isTrader">Is the user creating the offer a trader</param>
     /// <returns>RagfairOfferUser</returns>
-    protected RagfairOfferUser CreateUserDataForFleaOffer(string userId, bool isTrader)
+    protected RagfairOfferUser CreateUserDataForFleaOffer(MongoId userId, bool isTrader)
     {
         // Trader offer
         if (isTrader)
@@ -191,7 +191,7 @@ public class RagfairOfferGenerator(
             var playerProfile = profileHelper.GetPmcProfile(userId);
             return new RagfairOfferUser
             {
-                Id = playerProfile.Id,
+                Id = playerProfile.Id.Value,
                 MemberType = playerProfile.Info.MemberCategory,
                 SelectedMemberCategory = playerProfile.Info.SelectedMemberCategory,
                 Nickname = playerProfile.Info.Nickname,
diff --git a/Libraries/SPTarkov.Server.Core/Helpers/InventoryHelper.cs b/Libraries/SPTarkov.Server.Core/Helpers/InventoryHelper.cs
index 751e3dce..36c3e030 100644
--- a/Libraries/SPTarkov.Server.Core/Helpers/InventoryHelper.cs
+++ b/Libraries/SPTarkov.Server.Core/Helpers/InventoryHelper.cs
@@ -39,6 +39,7 @@ public class InventoryHelper(
         BaseClasses.FUNCTIONAL_MOD,
         BaseClasses.MOD,
     ];
+
     protected readonly InventoryConfig _inventoryConfig = configServer.GetConfig<InventoryConfig>();
 
     /// <summary>
@@ -213,7 +214,7 @@ public class InventoryHelper(
     /// <param name="sessionId">Player id</param>
     /// <param name="itemsWithChildren">Array of items with children to try and fit</param>
     /// <returns>True all items fit</returns>
-    public bool CanPlaceItemsInInventory(string sessionId, List<List<Item>> itemsWithChildren)
+    public bool CanPlaceItemsInInventory(MongoId sessionId, List<List<Item>> itemsWithChildren)
     {
         var pmcData = profileHelper.GetPmcProfile(sessionId);
 
diff --git a/Libraries/SPTarkov.Server.Core/Helpers/NotifierHelper.cs b/Libraries/SPTarkov.Server.Core/Helpers/NotifierHelper.cs
index 44208ebd..2e57720e 100644
--- a/Libraries/SPTarkov.Server.Core/Helpers/NotifierHelper.cs
+++ b/Libraries/SPTarkov.Server.Core/Helpers/NotifierHelper.cs
@@ -63,8 +63,8 @@ public class NotifierHelper(HttpServerHelper httpServerHelper)
         };
     }
 
-    public string GetWebSocketServer(string sessionId)
+    public string GetWebSocketServer(MongoId sessionId)
     {
-        return $"{httpServerHelper.GetWebsocketUrl()}/notifierServer/getwebsocket/{sessionId}";
+        return $"{httpServerHelper.GetWebsocketUrl()}/notifierServer/getwebsocket/{sessionId.ToString()}";
     }
 }
diff --git a/Libraries/SPTarkov.Server.Core/Helpers/TraderHelper.cs b/Libraries/SPTarkov.Server.Core/Helpers/TraderHelper.cs
index 2466bab5..cd298064 100644
--- a/Libraries/SPTarkov.Server.Core/Helpers/TraderHelper.cs
+++ b/Libraries/SPTarkov.Server.Core/Helpers/TraderHelper.cs
@@ -1,3 +1,4 @@
+using System.Collections.Frozen;
 using SPTarkov.DI.Annotations;
 using SPTarkov.Server.Core.Extensions;
 using SPTarkov.Server.Core.Models.Common;
@@ -29,7 +30,7 @@ public class TraderHelper(
     ConfigServer configServer
 )
 {
-    protected readonly List<string> _gameVersions =
+    protected readonly FrozenSet<string> _gameVersionsWithHigherBuyRestrictions =
     [
         GameEditions.EDGE_OF_DARKNESS,
         GameEditions.UNHEARD,
@@ -37,6 +38,11 @@ public class TraderHelper(
     protected readonly Dictionary<string, double> _highestTraderPriceItems = new();
     protected readonly TraderConfig _traderConfig = configServer.GetConfig<TraderConfig>();
 
+    /// <summary>
+    /// Get a traders base data from its nickname, case insensitive
+    /// </summary>
+    /// <param name="traderName">Nickname of trader, e.g. prapor</param>
+    /// <returns>TraderBase</returns>
     public TraderBase? GetTraderByNickName(string traderName)
     {
         return databaseService
@@ -244,7 +250,7 @@ public class TraderHelper(
     {
         if (rawProfileTemplate.InitialStanding.TryGetValue(traderId, out var standing))
         {
-            // Edge case for Lightkeeper, 0 standing means seeing `Make Amends - Buyout` quest
+            // Edge case for Lightkeeper trader, 0 standing means seeing `Make Amends - Buyout` quest
             if (traderId == Traders.LIGHTHOUSEKEEPER && standing == 0)
             {
                 return 0.01;
@@ -515,7 +521,7 @@ public class TraderHelper(
         string gameVersion
     )
     {
-        if (_gameVersions.Contains(gameVersion))
+        if (_gameVersionsWithHigherBuyRestrictions.Contains(gameVersion))
         {
             return Math.Floor(buyRestrictionMax * 1.2);
         }
diff --git a/Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/BotBase.cs b/Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/BotBase.cs
index ff9796ef..8c2e98df 100644
--- a/Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/BotBase.cs
+++ b/Libraries/SPTarkov.Server.Core/Models/Eft/Common/Tables/BotBase.cs
@@ -69,7 +69,7 @@ public record BotBase
     public List<QuestStatus>? Quests { get; set; }
 
     [JsonPropertyName("TradersInfo")]
-    public Dictionary<string, TraderInfo>? TradersInfo { get; set; }
+    public Dictionary<MongoId, TraderInfo> TradersInfo { get; set; }
 
     [JsonPropertyName("UnlockedInfo")]
     public UnlockedInfo? UnlockedInfo { get; set; }
diff --git a/Libraries/SPTarkov.Server.Core/Models/Eft/ItemEvent/ItemEventRouterBase.cs b/Libraries/SPTarkov.Server.Core/Models/Eft/ItemEvent/ItemEventRouterBase.cs
index 6a768d8a..a4a45582 100644
--- a/Libraries/SPTarkov.Server.Core/Models/Eft/ItemEvent/ItemEventRouterBase.cs
+++ b/Libraries/SPTarkov.Server.Core/Models/Eft/ItemEvent/ItemEventRouterBase.cs
@@ -80,7 +80,7 @@ public record ProfileChange
     public BotBaseHealth Health { get; set; }
 
     [JsonPropertyName("traderRelations")]
-    public Dictionary<string, TraderData>? TraderRelations { get; set; }
+    public Dictionary<MongoId, TraderData>? TraderRelations { get; set; }
 
     [JsonPropertyName("moneyTransferLimitData")]
     public MoneyTransferLimits? MoneyTransferLimitData { get; set; }
diff --git a/Libraries/SPTarkov.Server.Core/Models/Eft/Ragfair/RagfairOffer.cs b/Libraries/SPTarkov.Server.Core/Models/Eft/Ragfair/RagfairOffer.cs
index 43bbad0c..dd3c41ab 100644
--- a/Libraries/SPTarkov.Server.Core/Models/Eft/Ragfair/RagfairOffer.cs
+++ b/Libraries/SPTarkov.Server.Core/Models/Eft/Ragfair/RagfairOffer.cs
@@ -18,11 +18,7 @@ public record RagfairOffer
     public List<SellResult>? SellResults { get; set; }
 
     [JsonPropertyName("_id")]
-    public string? Id
-    {
-        get { return _id; }
-        set { _id = string.Intern(value); }
-    }
+    public MongoId Id { get; set; }
 
     [JsonPropertyName("items")]
     public List<Item>? Items { get; set; }
@@ -31,11 +27,7 @@ public record RagfairOffer
     public List<OfferRequirement>? Requirements { get; set; }
 
     [JsonPropertyName("root")]
-    public string? Root
-    {
-        get { return _root; }
-        set { _root = string.Intern(value); }
-    }
+    public MongoId Root { get; set; }
 
     [JsonPropertyName("intId")]
     public int? InternalId { get; set; }
@@ -128,11 +120,7 @@ public record RagfairOfferUser
     private string? _id;
 
     [JsonPropertyName("id")]
-    public string? Id
-    {
-        get { return _id; }
-        set { _id = string.Intern(value); }
-    }
+    public MongoId Id { get; set; }
 
     [JsonPropertyName("nickname")]
     public string? Nickname { get; set; }
diff --git a/Libraries/SPTarkov.Server.Core/Routers/EventOutputHolder.cs b/Libraries/SPTarkov.Server.Core/Routers/EventOutputHolder.cs
index fae38207..71653ff9 100644
--- a/Libraries/SPTarkov.Server.Core/Routers/EventOutputHolder.cs
+++ b/Libraries/SPTarkov.Server.Core/Routers/EventOutputHolder.cs
@@ -52,7 +52,7 @@ public class EventOutputHolder(
             sessionId,
             new ItemEventRouterResponse
             {
-                ProfileChanges = new Dictionary<string, ProfileChange>
+                ProfileChanges = new Dictionary<MongoId, ProfileChange>
                 {
                     {
                         sessionId,
@@ -79,7 +79,7 @@ public class EventOutputHolder(
                                 Points = 0,
                             },
                             Health = cloner.Clone(pmcProfile.Health),
-                            TraderRelations = new Dictionary<string, TraderData>(),
+                            TraderRelations = new Dictionary<MongoId, TraderData>(),
                             QuestsStatus = [],
                         }
                     },
@@ -255,8 +255,8 @@ public class EventOutputHolder(
     /// </summary>
     /// <param name="traderData"> Server data for traders </param>
     /// <returns> Dict of trader id + TraderData </returns>
-    protected Dictionary<string, TraderData> ConstructTraderRelations(
-        Dictionary<string, TraderInfo> traderData
+    protected Dictionary<MongoId, TraderData> ConstructTraderRelations(
+        Dictionary<MongoId, TraderInfo> traderData
     )
     {
         return traderData.ToDictionary(
diff --git a/Libraries/SPTarkov.Server.Core/Services/FenceService.cs b/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
index 95711259..eda5dbc6 100644
--- a/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/FenceService.cs
@@ -1755,7 +1755,7 @@ public class FenceService(
     /// </summary>
     /// <param name="assortId"> Assort ID to adjust </param>
     /// <param name="buyCount">`Count of items bought </param>
-    public void AmendOrRemoveFenceOffer(string assortId, int buyCount)
+    public void AmendOrRemoveFenceOffer(MongoId assortId, int buyCount)
     {
         var isNormalAssort = true;
         var fenceAssortItem = fenceAssort.Items.FirstOrDefault(item => item.Id == assortId);
@@ -1786,7 +1786,7 @@ public class FenceService(
         fenceAssortItem.Upd.StackObjectsCount -= buyCount;
     }
 
-    protected void DeleteOffer(string assortId, List<Item> assorts)
+    protected void DeleteOffer(MongoId assortId, List<Item> assorts)
     {
         // Assort could have child items, remove those too
         var itemWithChildrenToRemove = assorts.FindAndReturnChildrenAsItems(assortId);
diff --git a/Libraries/SPTarkov.Server.Core/Services/LocationLifecycleService.cs b/Libraries/SPTarkov.Server.Core/Services/LocationLifecycleService.cs
index 2f014fad..11430ec7 100644
--- a/Libraries/SPTarkov.Server.Core/Services/LocationLifecycleService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/LocationLifecycleService.cs
@@ -1117,8 +1117,8 @@ public class LocationLifecycleService(
     /// <param name="tradersServerProfile"> Server </param>
     /// <param name="tradersClientProfile"> Client </param>
     protected void ApplyTraderStandingAdjustments(
-        Dictionary<string, TraderInfo>? tradersServerProfile,
-        Dictionary<string, TraderInfo>? tradersClientProfile
+        Dictionary<MongoId, TraderInfo>? tradersServerProfile,
+        Dictionary<MongoId, TraderInfo>? tradersClientProfile
     )
     {
         foreach (var traderId in tradersClientProfile)
diff --git a/Libraries/SPTarkov.Server.Core/Services/MatchBotDetailsCacheService.cs b/Libraries/SPTarkov.Server.Core/Services/MatchBotDetailsCacheService.cs
index 9f0af264..413253e9 100644
--- a/Libraries/SPTarkov.Server.Core/Services/MatchBotDetailsCacheService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/MatchBotDetailsCacheService.cs
@@ -25,7 +25,7 @@ public class MatchBotDetailsCacheService(ISptLogger<MatchBotDetailsCacheService>
     /// <param name="botToCache"> Bot details to cache </param>
     public void CacheBot(BotBase botToCache)
     {
-        if (botToCache is null || botToCache.Id is null)
+        if (botToCache?.Id is null)
         {
             return;
         }
diff --git a/Libraries/SPTarkov.Server.Core/Services/PaymentService.cs b/Libraries/SPTarkov.Server.Core/Services/PaymentService.cs
index dd55bc75..cbb868cd 100644
--- a/Libraries/SPTarkov.Server.Core/Services/PaymentService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/PaymentService.cs
@@ -47,7 +47,8 @@ public class PaymentService(
     {
         // May need to convert to trader currency
         var trader = traderHelper.GetTrader(request.TransactionId, sessionID);
-        var payToTrader = traderHelper.TraderExists(request.TransactionId);
+        var payToTrader =
+            request.TransactionId != "ragfair" && traderHelper.TraderExists(request.TransactionId);
 
         // Track the amounts of each type of currency involved in the trade.
         var currencyAmounts = new Dictionary<string, double?>();
diff --git a/Libraries/SPTarkov.Server.Core/Services/RagfairOfferService.cs b/Libraries/SPTarkov.Server.Core/Services/RagfairOfferService.cs
index 49a59a51..722a10d5 100644
--- a/Libraries/SPTarkov.Server.Core/Services/RagfairOfferService.cs
+++ b/Libraries/SPTarkov.Server.Core/Services/RagfairOfferService.cs
@@ -190,7 +190,9 @@ public class RagfairOfferService(
         }
 
         // Handle dynamic offer from PMCs
-        var isPlayer = profileHelper.IsPlayer(staleOffer.User.Id.RegexReplace("^pmc", ""));
+        var isPlayer = profileHelper.IsPlayer(
+            staleOffer.User.Id.ToString().RegexReplace("^pmc", "")
+        );
         if (flagOfferAsExpired && !isPlayer)
         {
             // Not trader or a player offer