Gotham City Impostors doesn't hit Xbox Live until tomorrow, but you can get all of the Gotham City Impostors DLC you could ever want today.
The game now has over one hundred selections of downloadable costume pieces, ranging in price from $1 to $4 (80-320 MSP). A majority of the DLC is obtainable the old fashioned way - by playing the game and earning tokens. But it looks like players that want a quick way to unlockable costumes can just cough up some dough.
It seems that not even Batman is immune to the allure of micro-transactions.
Thanks for the tip, Edo!