hxxp://www.actonlinestore.com
i just got a new XP1600, 256DDR, mobo/case for 350
So they're good and cheap.
hxxp://www6.tomshardware.com/cpu/01q4/011031/index.html
has a review of the XPs versus P4
And it seems the XP1800 is the leader of the pack...w/ the 1500 as most bang for the buck.
so an XP2000 would prolly be over kill.