Don't expect your scores to get too high. 2800-3200 seems right for a comp like yours. I was at FRY's the other day and they had a computer with the Nvidia 6800 Ultra, Athlon 64 3700+, Watercooled, and with four sticks of what Im assuming was dual channel 512MB (=2GB) RAM since I couldnt see the kind of ram installed.
It was running 3DMark 05 and it scored only around 4660, and this is a non OC'ed comp. Since this was a top of the line computer I can imagine that your score wouldn't be anywhere near the 4000 range, so 3000s sounds about right.
NEW FOR COLLEGE!:
AMD Athlon64 4000+ SanDiego
MSI K8 Neo4/SLI
eVGA GeForce 6800 GT
Corsair XMS 1 GB TwinX 3200XL (TCCD)
SoundBlaster Audigy2 ZS
2 WD 36.7 GB Raptor HDDs in RAID 0
OCZ ModStream 520W PSU
Panisonic Panflo 92mm
Thermaltake Tsunami Case