Estimate on my build

I was wondering if anyone a can appraise what I can get out of my system. I do acknowledge some of the hardware is a bit outdated. But that's besides the point, it will run anything I throw at it fairly well.

Specifications
CPU: Intel Core 2 Quad 9650 3.00GHZ
RAM: 8 GB GSKILL PI 2GB DDR2 x4
GFX: nVidia GeForce GTX 550ti 1GB
PSU: Ultra 600 Watt
HEATSINK: Zalman Full Copper
MOBO: nForce EVGA 750sli FTW
CASE: AZZA Solano 1000 Full Tower
HDD: WD Velociraptor 10k RPM 150 GB

I'm wanting to sell my custom built system. But if I sell it within the next year, I don't want to look like a fool pricing it over what it's actually worth. All replies are appreciated.