Any legitimate ways to unlock all armor?

does anyone know the way to unlock all armor and skins without certain pre order codes and/or special offers? (7-11, DewXP, Doritos, etc) i see some really cool helmets that i want but did not pre order through that venue… example: dead eye and locus helmets. i pre ordered from gamestop and feel that my pre order bonus was second rate compared to some of the other pre order bonuses. i already unlocked the 1st raider helmet and other raider armor through waypoint. maybe i just want my cake and to eat it too but i want all the armor!!! can anyone help?

Ebay.