Hi!
Since you are on a "thight" budget I suggest the following parts from www.newegg.com. I suppose that you are able to put them together yourself.
Asus 48x24x52 CD-RW $37.00
CASE Dynapower Model# METIS 25$
AMD Athlon XP2500+ "Barton" 333FSB $93.00
Maxtor DiamondMax Plus 9 120GB 7200RPM $98.00
Albatron Nforce2 Mobo, Model KM18G PRO $99.99
2X GEIL 256MB PC-2700 MEMORY 2X30$= $60
Sapphire ATI RADEON 9700 Atlantis PRO $292.00
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Grand total of:...................... $704.99
(don't forget that the shipping will cost a few bucks)
The CPU is retail and comes with heatsink/fan.
Well there are many things one could discuss, for instance, I choose to spend the money on a good videocard instead of a faster CPU since I belive that this gives better longetivety. Especially for a gaming system. If you wan't to save some money on my suggested rig, go for a smaller HD, a ordinary CD/DVD-Rom (non burner). Don't buy less than a total 512 MB and 2 sticks of memory since thats required for the dualchannelddr (much better speed) to work. Don't forget to buy/reuse a FLOPPYDRIVE, its unfortunately a must have.
Mobo: the reason I choose this mobo is that it incorporates the outstanding Nforce2 APU soundsystem: Nforge! Belive me, it's very very good and you don't need a seperate soundcard with it. Check this THG article for more info:
http://www6.tomshardware.com/game/20030405/index.html
Beware that not all Nforce2 boards has this, instead many uses a cheap solution like the inferior realtek 650 soundchip. Another good board that has the Nforge sound is the famous ASUS A7N8X Deluxe. Basically if buying a Nforce2 board, you should make shure it has the MPC-T southbridge!
Also if you can muster some more cash, try getting a case with more power (PSU). Although I think that 300W is enough you might wan't to be on the safe side of things and get 350W.
Anyway GL
TURK
PS why a AMD rig? Read THIS link fore more on that:
http://forumz.tomshardware.com/hardware/modules.php?name=Forums&file=viewtopic&p=665271#665271