Cool thanks for the replies. Yeah I figured 400 would be a possible number, was kinda hoping 600.. at least that would pay for what I put into it. @kcsmacker- I haven't done much in the way of add-ons and the PSU is a 600w Thermaltake.
When it comes to electronics you will never get what you put into a old system. This is true for anything. I agree with a previous poster. If you want to sell it outright sell it for 250-300.
Parting it would still be my suggestion, keeping what you can for the next build.