I'd say if it cosmetically looks nice $200. If it looks beaten, $150. Used PC parts just don't rack in much dough. I think it depends on who you sell it to. If it is an IT person they will probably pay less. If you know somone looking for a cheap deal then you can probably get $250 or so. Vista Ultimate isn't cheap, but then again if it's OEM you are stick with it on that machine.