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.
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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!