Barkley, Merchant of Baubles

Barter {u}{b} ({u}{b}: Create a colorless Clue artifact token with "{2}, Sacrifice this artifact: Draw a card." Target opponent creates two colorless Treasure artifact tokens with "{t}, Sacrifice this artifact: Add one mana of any color to your mana pool." You and target opponent may exchange control of these tokens.)
If target opponent agrees to barter, put a +1/+1 counter on Barkley, Merchant of Baubles.