One of the more annoying drawbacks of Merchant Guild is that you can't use the tokens you gain from it. Well, with Black Market, you can! Create an engine that can play at least one MG and then the Black Market, buy something from the Black Market, gain coins, spend them in the Buy phase. Now, this is probably counterproductive unless you really want cards from the Black Market or have the ability to play tons of Merchant Guilds, but it's yet another addition to the "cool stuff BM can do" list.
