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. For a price.
The game now has over one hundred selections of downloadable costume pieces, ranging in price from $US1 to $US4 (80-320 MSP). Looks like players that want more than just the in-game unlockable costumes will have to pay up.
It seems that not even Batman is immune to the allure of micro-transactions.
Thanks for the tip, Edo!