It turns out the Compy 500 was really several pieces of crap put together. However, you are able to sell it to a local sleazeball named Ungurait for 500000 dollars.
You go to Bubs' and buy that computer, then leave. When Homechool Winner gets back, Bubs' tells him "Get lost. I sold you're computer." and shoots him.
YOU FRIGGIN' WIN!