I just got some stuff a coupla weeks ago;
Abit nforce2 motherboard, Athlon 2400XP+ (wi' fan), 512MB DDR400 (single stick - buying a second when I settle on a new case) & a GF FX5600 (Gainward, Ultra 760 or something) off of Dabs.com - came to about £350 all in all....
Unfortunately, my PSu in the old case appears to be dodgy (getitng voltage errors in the health check app), and the case itself - whilst being an ATX one - is so poorly designed that the drive cages actually obscure all but the slowest DIMM slot, and also make it extremely difficult to fit in the floppy cable (eventually had to tuck it in behind the drive cable)........
NB: - Athlon is the CPU (AMD - actually runs at around 1.5GHz but has comparable performance to a P4 of 1.7GHz, hence the 1700+ bit), and Biostar will be the Motherboard.