A pre-built computer in that price range just isn't going to get you that kind of performance, not with mods, sorry. I'm on a $1,500 computer that I built (or am currently building/upgrading? Bah, semantics) and I occasionally drop down to high 120s for fps while running Direwolf20 and that's what.. 40 mods? I just don't see it being possible for a pre-built PC in that price range to perform almost as well with more mods. That said, if you're set on it being a pre-built, here's these starting at $589 http://www.ibuypower.com/Site/AMD_FX_Lobby