I don't like that you can go through the trouble of doing this and trashing a Platinum, then your opponent buys this card right before his reshuffle, then she gets to take the platinum you wasted your turn and card to trash. The way to play this card seems to buy 2 before you use the trash ability.
Why isn't the self-trash switched? Each one is trashed when they claim an amazing card, not when they trash from the supply pile.
BIG ISSUE: Over time, the trash may will with Beneficiaries, which chain together to claim each other indefinitely. HandB1 claims TrashB2 and trashes itself and SupplyB3. HandB2 claims TrashB3 and trashes itself and SupplyB4. HandB3 claims TrashB1 and trashes itself and Gold1, etc. forever.
Using this on Platinum seems a little too impactful anyway. No card says "gain a treasure". The closest thing is Thief, but somebody had to get the $9 for platinum.