The Slicer of T'pire Weir Isles

The Slicer of Tapeer-Wheer Isles is a stone which, on a successful Persuasion check, can be traded to anyone for the most valuable thing they have in their possession. Taako purchased the stone from Fantasy Costco, then immediately traded it back to Garfield for the Flaming Poisoning Raging Sword Of Doom.