In other words, Black Market with a predictable choice of cards. That would be really interesting, but in my mind OP - if there is a good card like Mountebank everyone is going to open black market and the game is almost entirely decided by the luck of the draw. However, if the cards in this "black market" deck were the same ones available in the supply, but at a discount, I might actually want to buy the "black market," especially if fairgrounds is in play.