He's right, you can build a much better one for much less. If you like to waste money, you could buy an Alienware PC that is faster than that one and also costs less, but it will still cost more than building one.
Well, you should look for i5 2500k, gtx 580 or dual 6970's, 8Gb of ram, p67 mobo, 700W PSU, case which ever you want, some normal big hard drive and SSD for OS. If you need ready list from newegg, tell me.
This. Though i'd advise you to go with either a crossfire setup with 6950's instead of 6970's. You'll save some money there as well as saving money instead of going with a single GTX 580.