Black Market
Set:
Promo
Type:
Action 
Cost:
3 Reveal the top 3 cards of the Black Market deck. You may buy one of them immediately. Put the unbought cards on the bottom of the Black Market deck in any order.
(Before the game, make a Black Market deck out of one copy of each Kingdom card not in the supply.)
Comments
The People's History of the
The People's History of the United States is by far the best Black Market combination I've played with. We used Intrigue for the Black Market deck. People were trashing 3-cost cards and giving the victim Black Market cards in return, so the deck got churned through fairly quickly.
Example of Black Market as
Example of Black Market as the Bane card for Young Witch:
Royal Demands