I understand being out of work, needing money for rent, and having to part with your favorite desktop. I’ve been there before. However, your desperation does not a good deal make.
Ohh, pretty colors…
That’s about the only thing going for this desktop. When they said that they “spent a lot of time and money investing in this rig”, they apparently thought that meant that they would get back all that they put into it. Sadly, technology depreciates worse then cars, houses, and Twinkies.
Lucky for us, Newegg has all of the parts (except the motherboard). I found the motherboard on eBay for <$100.
All told, you could put this together now for about $1,200 “new”. Your ~2 years of sentimental value and wear/tear isn’t worth $800 more.