Fixed null being thrown when searching for an item that has no offers requiring it

Libraries/SPTarkov.Server.Core/Helpers/RagfairOfferHelper.cs

@@ -167,8 +167,9 @@ public class RagfairOfferHelper(
     /// <returns>Matching RagfairOffer objects</returns>
     public List<RagfairOffer> GetOffersThatRequireItem(SearchRequestData searchRequest, PmcData pmcData)
     {
-        // Get all offers that require the desired item and filter out offers from non traders if player below ragifar unlock
+        // Get all offers that require the desired item and filter out offers from non traders if player below ragfair unlock
         var requiredOffers = _ragfairRequiredItemsService.GetRequiredItemsById(searchRequest.NeededSearchId);
+
         var tieredFlea = _ragfairConfig.TieredFlea;
         var tieredFleaLimitTypes = tieredFlea.UnlocksType;
         return requiredOffers.Where(offer =>

Libraries/SPTarkov.Server.Core/Services/RagfairRequiredItemsService.cs

@@ -12,11 +12,14 @@ public class RagfairRequiredItemsService(
 {
     protected ConcurrentDictionary<string, List<RagfairOffer>> _requiredItemsCache = new();
 
-    public List<RagfairOffer>? GetRequiredItemsById(string searchId)
+    public List<RagfairOffer> GetRequiredItemsById(string searchId)
     {
-        _requiredItemsCache.TryGetValue(searchId, out var list);
+        if (_requiredItemsCache.TryGetValue(searchId, out var list))
+        {
+            return list;
+        }
 
-        return list;
+        return [];
     }
 
     public void BuildRequiredItemTable()