Hey man, I just upgraded to 8800GT from 7800GT SLi. I have 2 XFX 7800GT if you would like to buy one I will sell it to you for 75 bucks. Just drop me a PM if you want it. Don't have the box anymore but cards still look and work like brand new.
I have a pny 7900gs here with all the original stuff that came with it including the box. Its about almost 1 year old. I can sell it for 75 with original cooler or 90 with zalman vf900.