Tested this in sandbox just now. The 1 badge NPC in the shop will perform an additional exchange for an item each time you have selected "No" without leaving the menu. Example: 3 badges in inventory (can be same or unique, doesn't matter) Talk to the 1 badge FOmarl NPC Select any item. Select "No" Select any item. Select "No" Select any item. Select "Yes" NPC performs exchange for the last selected item, and then the NPC will perform the same exchange 2 more times. If you selected "No" too many times, then you'll get a server sync error eventually. If you ever select "No" and then try to leave the menu by selecting "Nothing" in the list of items, then the NPC attempts to perform an exchange but it looks like nothing happens. You still get a server sync error saying you don't have any badges, but it looks like nothing was exchanged? After getting disconnected and relogging, I still had the two badges in my inventory.