i would like to build a 1u or 2u server with p3 and 512mb ram as well as 80gig harddisk.. wats the budget i need to fork out to get that?

Depends on several things. Like hardware quality.

I'd recommend checking out a vendor like, http://www.online-spectrum.com/ and see what they charge.

Let's say you go middle road with a 1U Supermicro system, you're looking at about $850 or so plus your time.

George

check out sites like pricewatch.com pricegrabber.com for ok pricing. You may also want to check out thread how to build cheapo 1u server

http://www.webhostingtalk.com/showthread.php?s=&threadid=67744

tigerdirect has some nice 1U barebones..

big company, can't expect too shabby of a product from them..

built me a pretty sweet small business server for a client for under $2000

You shouldn't build it yourself unless you know how to achieve proper cooling etc.
This server would run to about $700 at www.interpromicro.com

And if you go the pricewatch route, be careful of shipping. Ordering from the cheapest vendor for each component means you'll probably pay several different shipping fees.

George