Ah, I misread, I thought there was a mana cost on the tap. No, this is basically broken. Heck just coming in with haste and making two treasures for free costing you a net 1 mana to get onboard is pretty dang good. I think the only saving grace is there's no blue in this, so most of the real good untapping is locked up.
It's got haste too, try it with flicker effects.
maybe not infinite treasure, but this is definitely abusable with any good untap engine.