There should be some kind of mechanic where you can put the thing somewhere and retrieve it later. Sort of like a ender chest, but with multiple, mutually-exclusive repositories.

For example, you could sell the item to a particular NPC, and someone else from the NPC’s same guild in a different city might have the item, but only if you ask about unusual items. “Oh yeah I bought this the other day from my counterpart in Lombard: <the item you sold>”

Some way to free up inventory, and take a chance the item will still be in your world later.