unfortunatly computer hardware really dosnt hold its value at all.
what you have to price up is what someone can build with current parts that is the same spec. and ur going to be looking at being able to sell it at about 1/2 to 2/3's of that price.
ur looking at a little more power than the AMD Based Basic gaming computerhttp://www.tomshardware.com/system-configuration-recommendation-51.html[/ur]
its going for around $462. (no software, monitor, keyboard or mouse)
ur going to be looking at around $500-700 for the entire system IMO.