Yeah sorry there Kusai but that's what we get when we keep our systems so long. I'd say judging from Craigslist prices you might get $30-40 at best but that depends on who'd want it. Most on Craigs are looking for new-ish stuff. Don't know where you are so your market may find someone willing. Otherwise you could try listing the parts on eBay, etc. Longshot and not worth much plus you have to deal w/fees and postage. Worth the time?
I'd also opt for DIY, it's pretty easy as long as you spec out everything. I have seen some i5 systems on Craigs for $400 and I salivate. I'd slap more ram and a card in there if the PSU could handle it.
A quick search leads me to believe an i5-2500 or old Phenom II X4 minimum and a GTX 750 or R7 260X min would do for your game. Also Win 7 64b or 8 64b, don't know why sites recommend 64b OS's for that.
You could get an old Phenom II X4 (or even X2 or X3 and unlock it) system for cheap and throw in a newer card but I'd really suggest you just svae up for modern hardware that'll last down the pike for the next latest and greatest games.