the100thballoon:
Okay, these prices are off Newegg, I don't buy from US sites, so can't price as well as you probably did, but Newegg is generally pretty close to the lowest prices available.
Athlon XP 4000+: $542.99
Motherboard: $120 (Am lazy and lowballing this instead of finding a price)
RAM: $650 (OCZ PC-5000 platinum, found a low price on a Canadian site, converted to US currency and then rounded down, so it might be more expensive)
Hard drive: $80 (You don't really want the fastest 160Gb hard drive. That would be a SCSI drive, and would require a seperate controller to run.)
Video Card: $500 (Again, I got lazy and estimated low, for an X850XT PE)
Sound card: $60
Mouse: $5
Keyboard: $5 (Nice mouse and keyboard, eh?

)
Case: $30
PSU: $100
Optical Drives: $70
This is over $2150, care to point out where you're cutting any corners?