Hi, welcome to THG.
Ok... I'll take a shot at this, let's see what I can scrounge up. Btw, for reference, I will be using Newegg.com for prices/components.
Case: Pure guess here... Lian Li Mid-tower ($65) - Good company, and you probably won't want to spend more than $60-70 here. This is one of the components I go high or low on. (One of my comps has no cover, baring its parts for all to see on a Heavy old frame, the other sits comfortably in a high end 5-fan case).
<A HREF="http://www.newegg.com/app/ViewProduct.asp?DEPA=1&submit=manufactory&catalog=7&manufactory=1375&description=&order=Description" target="_new">Case</A>
Cpu: XP2400 ($85) - Fairly good speeds, great OC potential (mine runs at XP2600 speeds, 200fsb)
<A HREF="http://www.newegg.com/app/viewproduct.asp?description=19-103-336&DEPA=1" target="_new">Processor</A>
*Edit* XP1700 is an excellent 2nd choice; it's highly overclockable, and at $41 quite a deal.
Motherboard: Epox 8RDA+ ($85) - nForce2 board, good performance, inexpensive, stable, and overclocking friendly. First came out around dec '02 I believe.
<A HREF="http://www.newegg.com/app/viewproduct.asp?description=13-123-191&DEPA=1" target="_new">Motherboard</A>
RAM: 512MB (256x2) Corsair PC2700 CAS 2.5 ($74) - I have a hard time deciding where to draw the line for price/performance on RAM, honestly. This is where I usually splurge. PC2700 ram should be just fine. If there's room later for more money to spend, I'd say spend it here, and get some CAS 2.0 PC3200.
<A HREF="http://www.newegg.com/app/Viewproduct.asp?DEPA=1&submit=manufactory&catalog=147&manufactory=1459&description=&srchFor=2700" target="_new">RAM</A>
Hard Drive: 80GB 7200rpm Western Digital ($82) - Has 8MB cache, great performance, and nice price at ~$1 per GB.
<A HREF="http://www.newegg.com/app/viewProduct.asp?description=22-144-122&depa=1" target="_new">Hard Drive</A>
Video Card: ATI Radeon 9500 pro ($189) - Not sure about this one, probably still the best bang for your buck for video atm. Maybe a 9000 instead to cut the cost. Video cards are so expensive :tongue:
<A HREF="http://www.newegg.com/app/Viewproduct.asp?DEPA=1&submit=manufactory&catalog=48&manufactory=1126&description=&srchFor=9500" target="_new">Video Card</A>
DVD: Lite-On 16xDVD player ($31) - Good quality, excellent prices on Lite-On.
<A HREF="http://www.newegg.com/app/Viewproduct.asp?DEPA=1&submit=manufactory&catalog=55&manufactory=1336&description=&srchFor=dvd" target="_new">DVD Player</A>
Sound Card: None needed; motherboard has fine 5.1 integrated sound.
Floppy: Random $10.
Network: Integrated in motherboard.
OS: Windows XP Home ($93)
<A HREF="http://www.newegg.com/app/viewproduct.asp?description=37-102-014&DEPA=6" target="_new">Windows</A>
Monitor: Forgot if you need a monitor; I'll check shortly.
Comes to a total of $714 w/o a monitor so far.