You can also get into this situation tossing a teleporter stone into the back room of the mage Kistandalius' shop; he will teleport you out before you have time to pick it up again.
Place the teleporter you still have in a barrel, or something, and download the inventory files to get a new set, as Lockmar posted.
If you are close to hitting the gong, you can just leave it and get a replacement ancient pyramid shortly after getting to the wastelands.
