How much should I sell this computer for?

In my opinion you can go buy an HP complete system with monitor mouse and keyboard included for 500.00 at wal-mart. I sold a system used just like that one for 250.00 which is about the average price for a used system in good shape. I was asking 400 to start and negotiated to my low end of 250. It really all depends on where you are located. Check around the local repair shops and used computer shops to compare their prices and go from there.