Just a few days ago, we let you all in on Best Buy’s little experimental promotion to compete with GameStop — they were pricing their new game titles at the cost of a used copy of that same game. Well you can’t be too terribly surprised to learn that GameStop has retaliated with some remarkably low prices on used copies of their games. Actually, it’s not so much a retaliation as it is a “oh yeah? So you’ll go this low?” kind of retort.

Among the deals, you can nab a used copy of inFamous or Ghostbusters for PS3 for $40, or Halo 3 for $25. Being that Best Buy would match these prices, that’d come at a huge loss for them. Being that GameStop’s copies are used, it’s no sweat off their back. They probably buy the games for what… a couple bucks? I kid… sort of.

For those of you eager for competitive deal-making, you’ll have to live in West Jordan, Utah. The same city, if you’re keeping up, where Best Buy is conducting their little experiment. Will this get ugly? We’ll see. Will it last and last? Probably not. If Best Buy kept it up they’d be losing a mint. If GameStop kept it up they’d… well they’d still make money but they wouldn’t be gouging by quite as much. And I think we can all agree that that would just be a travesty.