RenovationWork/RenovationWorkFileImplement/Implements/ShopStorage.cs

@@ -85,12 +85,14 @@ namespace RenovationWorkFileImplement.Implements
             }
             return null;
         }
+        
         private bool CheckSell(int RepairId, int count)
         {
-            count -= _source.Shops.Select(x => x.ShopRepairs.Select(y =>
-            (y.Value.Item1.Id == RepairId ? y.Value.Item2 : 0)).Sum()).Sum();
-            return count <= 0;
+            int availableCount = _source.Shops.Sum(x => x.ShopRepairs
+            .Where(y => y.Value.Item1.Id == RepairId).Sum(y => y.Value.Item2));
+            return count <= availableCount;
         }
+
         public bool SellRepairs(IRepairModel model, int count)
         {
             var neededRepair = _source.Repairs.FirstOrDefault(x => x.Id == model.Id);