Well... where to start. I recently bought Mass Effect 3 (360) from CeX and it contained THREE Cerberus codes, which I wasn't expecting any of. I tried the first one and it worked, meaning the seller must have been offline or something, and this left me with TWO more codes.
Catch-22 is that I don't know if they work, but can't check without using them, so I am selling them in a sale or return way.
DLC is £10 so i'm starting the offer at £5 (Image is Upsidedown)
FOR GAMERS... FROM GAMERS!
IF the code DOES NOT work (and I will need photographic evidence) I will refund 100.00% of the paid total. Obviously you will require proof of who I am so I will send a photo of the codes (Partially Censored) and and I.D you require so you don't worry i'm running off with your money