You find a small section of the shop given over to mostly pieces of chrome armour and replica plasma weaponry. Some of them even have proper glowing bits. On proud display in the center is a full-scale replica of the Master Chief's MJOLNIR battle armour. It stands at about 7-feet; you're not even sure if you'd be able to wear it.
At it's feet there are much smaller replica costumes. You pick out a grunt methane tank, a crude plastic jackal shield, and the head piece for a set of hunter armour, among others. Neat.