Seems about right. The GF4 ti is holding you back a bit, and that SDRAM probably doesn't help big time, but mainly I think the ti is holding you back in 03. 3d 2k3 uses a lot of DX9 stuff so if your card doesn't support it your in trouble.
You can compaire your scores to others with simiar configs at
http://www.futuremark.com formaly known as
http://www.madonion.com
From the results I got other people are getting 2000 at the top end to about 1400 or so at the bottom end. Like I said your mem and actually possibly your mobo are both holding you back a bit along with your vid card, but thats only in 3dmark2003. Real world stuff could be a lot different because not many games use DX9 stuff yet. Your system is pretty kickass IMO