User blog comment:RayShepp654/Blood Dragon Armor HELP/@comment-730941-20100904141647

For the retail versions, at least, the Blood Dragon Armour required a download code to be used to unlock it in both games.

Did GameStop specifically say that the Armour set was included in the sale? If they did, and you didn't get a code, I'd contact them for help. If they didn't say anything, it's possible the Armour set was only available for retail copies, or sales of the game when it was first released.

Sorry that I can't help more.