All this discussion is pointless.
You lost the money.
Driving there and confronting him or doing something to him would not make up the loss to you, would cost you to get there, and might lead to more trouble than you already have.
You don't really have a criminal case. Even though he took advantage of you, all you have is a civil case. Filing a lawsuit for that and traveling to the court proceedings would cost you more than you would recover.
Plus you might no even win the case. Can he claim the unit was shipped via USPS and that you didn't receive it? If so, you might not have a case.
$50.00 for a functional Amiga? You probably should have looked at that with a grain of salt. The funny thing is you can get an Emac on Ebay for about that. And if you're defrauded you can get your money back.
Swallow your pride, Admit that you didn't make a good decision and buy the Mac.