Alienware is running a promo giving away keys for an Iron Man costume "Heartbreaker" It lasts until all are gone. Be warned though, people are having trouble getting their key to work. Unknown if having Iron Man unlocked or not is the cause, as there are several conflicting reports. With the trouble the game is having at launch, this isn't shocking but is worth a try anyway for those interested.

http://www.alienwarearena.com/giveaway/marvel-heroes-iron-man-heartbreaker-armor-costume-key-giveaway/

It keeps telling me the key expired, I asume it because I do not own Iron Man as a character.

@bismarck: Yup, you have to own the characters to be able to use a costume code for it.

Looks like they have the problem solved. No need to own IM at all. Just redeemed my key.

https://forum.marvelheroes.com/showthread.php/27694-Iron-Man-Heartbreaker-keys-now-working-again