I spent right about $1,500 I didn't need the keyboard, mouse, or monitor. I have a nice machine for AH, and just about anything else I care to run.
It was a snap to assemble. If you have replaced a vid card, or ram you should be able to assemble a computer.
E8400
ASUS P5E
XFX 8800 GTS 512MB PCI 2.0
4 GB Corsair ram
150 GB raptor HD
Antec 900 case
Rosewell 850W PS
ASUS HDDVD DVD drive
XP pro