I have to agree with jarlmaster why not just keep the computer it is great for an upgrade. The only reason I can think of is that you spent way more than you intended and now need money for the computer. Well I will say this for it if I had the money to do it I might buy it myself as it is really nice the way you built it. I don't however believe you will get what you put into it though.
The economy being the main reason that you can't get that much. I wouldn't take anything less than at least half and probably more of what you put into the computer.