You guys are both wrong- I built my current system for under $500- I didn't need a h/d, cd, or video, but even if you add a good video card, it's still under $500- here's what I got
AMD Athlon64 3000+
MSI K8T Neo
1 GB Mushkin DDR400
Well ventilated, cool looking, lit, windowed case
Mobo has built in 5.1 channel surround sound (w/ optical output), gigabit ethernet, I've got 7 USB 2.0 ports, and Firewire.
This cost me approx. $350, add a good card for say 150-200 and total price is around $500. Just look for the right prices and you can build yourself a good system for $500. I say go for it