I too am building a new core2 system, and am going to sell the old one. A general price would be nice, with possibly parting it to make more money....
Dell Base with XP Pro cd's and keys.
P4 2.8ghz with HT
XFX 6800GT 256 (3 months old)
1.5 Gb Ram (2x256mb Kingston Ram & 2x 512mb Corsair Ram)
200gb 7200 rpm
120 gb backup drive 7200rpm
hopefully I can get about 400 for it, but then again, maybe I'm way to optimistic...