Quid Pro Quo: Action. $3
Reveal the top three cards of your deck. Trash a card that your opponent chooses and place the remaining cards back in either order. You may then gain a card costing up to $3 more than the trashed card.
The original version of this instead allowed you to choose the trashed card and gave the opponent the choice of a card costing exactly $3 more to replace it with. I rejected this when I realized that it anti-synergized with pretty much every other card, given that an increase in variety gave your opponent more bad options to damage your deck with. Under the current model, this card can act either as a limited expand or as a terminal lookout.
Currently, you may expand a trashed curse or copper into a copy of Quid Pro Quo. Is this balanced, or should the cost be adjusted to $4?
Note that in the late game, your opponent can empty the province pile by trashing a province of yours, and that this card holds little value in terms of cleaning up curses, as the opponent can likely target your copper instead.