if you do end up getting a new sound card, i would recommend the hercules fortissmo II..very nice card for around 40 bucks
video card: radeon 8500le would be your best bet right now for around 100 bucks
hard drive: prolly, a 40gig; i would recommend maxtor - newegg price of 76 bucks
case: as long as you are at newegg, go with the evercase with a 300 watt psu for 40 bucks
ram: you could probably settle for 256 crucial for around 50 bucks
cd/dvd: toshiba dvd-rom is going for 40 bucks now
proc: amd athlon xp 1700 for around 100 with a hsf
mobo: a number of good boards sell for around 70-80 bucks
MSI KT3 Ultra, SOLTEK SL-75DRV5, Gigabyte GA-7VRX all based on the KT333 chipset
this comes up to about 530 bucks..so you might want to drop that sound card, settle for a cdrom, and possibly go with a slower cpu to hit your budget🙂