That's because the demo isn't 100% optimized for limited inventory (since I added the feature over what was already there). What's happening basically is that I'm adding a lot of items to the party in the initialization event (regardless of any limitation). The result you get there is because the plugin actually takes into account only "trade items" (meaning items used in Trade Shops), while I'm creating the shops only when the player talks to the shop PNJ for the first time. So while some shops aren't yet created, some items aren't considered as trade items. There are actually 2 ways arround that : 1 - Create all the shops from the start (but it also means, produced items might pile up too early in the game). 2 - First create a dummy Trade Shop (not accessible by the player) with all the trade items.