I'd buy it, new, even for a console. You don't want to get icky othergamer germs inside your Xbox or PlayStation. They cause red rings of death or yellow lights of despair.
You know, my only experience renting a product on optical media some nine years ago has forever scarred me. It was a DVD of, er, um, well,
Charlie's Angels.

Anyway, someone had spilled, to my best guesstimation,
honey all over the DVD. Fortunately I noticed it before placing it ever so gently into the tray of my precious DVD player.
Never again. I mean, VHS players were a dime a dozen back when, so who cared if the rented copy of
Back to the Future you shoved in was in fact some kid's half-eaten PB&J sandwich?
Anyway, that's why you should buy
Dragon Age: Origins. Only not on VHS.