[TheVermin23]

typically, MMO's will have thier own marketplace to buy things, ingame, with game currency. especially with cross platform games.
in many korean MMO's, however, they had alot of 'market' items that you pay actual money to have the special items. they were free MMO's so it was thier way of getting paid.

if there are items to buy, like you foresee, i hope they have personality. like- a top hat. or a monacle LOL.
"Dashing good fight, i say."
"Mmm yes.... indubitably."

or tattoo's or something.
pieces to a Masterchief spartan outfit would be cool, but it's copyright