Well once again Z, it's going to depend on speed, brand, what kinda features you'd want on a mobo, where you shop, what size die the proc was made on, and many other things. Ya gotta know what ya what or at least give people an idea cause other wise you end up paying more then you need to for something that's either too much or too little and you end up wasting your money. I'll make a personal recommendation of what you should get though.
Found all this on NewEgg:
AMD Athalon XP 2000+ 1.67ghz $79
Artic Silver 3 3ounce tube $6
ThermalTake Volcano 7 $15
ThermalTake CPU Shim (the new revision) $5
MSI KT4 Ultra $92
Ok now for the breakdown. The proceesor is an oem, which means you wouldn't get the fancy store packaging or the hsf. The upshot is you save 20 bucks. Why did I recommend spending $26 on new hsf fan stuff as opposed to $20 for the one with it? Well AMD stock fans are pretty simply garbage and these ones run far too hot for them. This means you would have spend the extra 20 bucks plus the 26 for the thermal grease hsf and shim(it'll keep your from accidently breaking the proc while trying to put the hsf on its worht the 5 bucks versues the 79 for the new proc). The chipset on the mobo is the VIA KT400 which is probably the best athalon chipset with some arguing the nforce2 but thats not worth the extra cost. Don't know what kind of memory you have but this runs up to ddr400 so if your still running sdram thatll be at least another 100 but it's more then worth it. Also don't try and put in pc-100,133 or it'll fry the memory. I also would go with at least pc2100(266mhz) while id recommend pc2700(333mhz) but dont go lower then 2100 or itll inhibit the busses far too much.
What I gave you there is $197 plus s&h. Then you can get samsung 512meg pc2700 ddr for 103.50. That puts you at 303.50. Might as well go with the 2700 since its only 1.50 more then the 2100. I know this may seem alot but think about if u spend like 50 now and then in 6 months u need to upgrade again spend another 50 then you have to buy all this cause your mobo cant handle faster stuff and youve spent more then youve spent now with a mobo that can be upgraded into. I do still recommend the video card also even though it will add another 80 dollars or so. My reasons being that you dont even have a gf equivalent card right now making that the bottleneck of your system. If you dont keep everything in decent balance then you might as well not upgrade at all. Plus very few new games will run on your card. The mobo's also 8x which wouldnt mean much to a card like the 9700 but to one like this thats very good for the price the extra bandwith only helps it. Well that bring's it all to a bit under 400 which for all that ive recommended is quite a good deal. Forgive the loseness in punctutaion and such as it's late and this got far longer then i expected. Let me know if u have any questions.
-Trevor
-amusedtoe