diff --git a/src/AcDream.App/UI/Layout/VendorUiController.cs b/src/AcDream.App/UI/Layout/VendorUiController.cs
index f53b77b4..b1edcc8b 100644
--- a/src/AcDream.App/UI/Layout/VendorUiController.cs
+++ b/src/AcDream.App/UI/Layout/VendorUiController.cs
@@ -1959,6 +1959,11 @@ public sealed class VendorUiController : IRetainedPanelController, IItemListDrag
             return;
         UpdateBuyTransactionText();
         UpdateSellTransactionText();
+        // Post-buy gate finding (2026-08-08): the Items tab's cost sentence
+        // carries "(you have Np)" too — a coin change must repaint it, not
+        // only the Buying/Selling tab summaries, or the purse reads stale
+        // until the next selection click.
+        RefreshSelectionDisplay();
     }
 
     /// <summary>