That's a tough pill to swallow, sorry to hear about all of the problems. I think there is a lot of good informaiton from other people above about trying to work on it yourself to learn more about the machine. Once you start working on some of the issues, you will realize most of the items you mentioned are fairly easy to correct. Ask questions here for anything you need help with.

I'm curious to know if you paid $3600 initially and received $600 back making your total purchase $3000 or if you paid $4200 initially and received $600 back for a total of $3600 final purchase price.