OK Chris, good job doing the PPI!
Negotiate with the seller, and be firm. What is he willing to pay per hour? Can he provide the new parts? Will the P-dealer accept the parts? What does the P-dealer charge per hour? Within the answers to these questions you should be able to constuct a win-win negotiation.
Some money may still come out of your pocket, but you will have piece of mind the work was done properly.
One more thought. What about the guy that did the PPI? Can he share in the responsibility of "missing" the potentail obvious failing a/c compressor? I would ask him to refund a portion (25-50%) of your PPI fee. Worth a try.
Good luck. Brighter days are in front of you.
And you will have a grin like this guy-
