Mosq is absolutely right. You'll need a video card to go with that. I'd recommend an nvidia 7800 or 7900 of some sort, but a 7600 would work too. Much below that and you're losing a lot of performance for whatever money you save.
You can probably save money by looking at best buy, but actually buying from newegg or another online source. Only Frys is cheaper, but I've had some really bad experiences with frys return policies. Newegg is pretty easy and they have reasonable prices.