similar/identical parts, if you grab them from newegg (where possible):
mobo – 100
cpu – 100
psu – 150
case – 120
ram – 35
hdd – 50
video – 100
sound – 130
tuner – 65
modem – 10
dvd – 30
dvd w/lightscribe – 30
floppy – 7
cpu heatsink – 45
keyboard/mouse combo – 35
windows xp pro – 140
windows xp x64 – 140
windows vista business 64-bit – 300
total on parts alone: $1,587
(and yes these are current prices of the hardware that’s in it, not what they were when i put this together or what similarly high-end things today would be 
)