well u didn't specify which company.
still try these
FORMAT will be
eg:model(processor, RAM, HDD, OS)---->price
Presario
--------
1)c506(Cel 1.86,256MB,80GB,DOS)--->24k
2)c555(Cel 1.86,256MB,80GB,DOS)--->24.7k
3)6406(Cel 1.6,512MB,80GB,DOS)---->27.1k
Acer
----
1)Aspire 3683(cel 1.6,256,80,linux)--->22.5k
2)Aspire 3684(cel 1.86,256,80,linux)-->22.5k
3)Aspire 4310(cel 1.6,512,80,linux)--->23.9k & 27.5k(2 models)
4)Aspire 5052(tur 2.2,512,120,linux)--->28.7k
Lenovo
-------
1)3000y500(cel 1.6,512,80,DOS)--->26.2k
*****************
prices may vary by a bit. do check out the one u like the most.