Sorry to hear that happened to your friend. Especially to a newcomer to the hobby.
I am also a newcomer with only 1 successful purchase under my belt. That purchase I drove to California to pick up in person and was from a fellow Pinsider.
I find that most Pinsiders will go out of their way to help another Pinsider just because of their true passion for Pinball. I have had Pinsiders offer to look at a machine that is close to them to make sure it is what is advertised. I have asked other Pinsiders if they have heard of a particular seller.
My point is if we can work together as a group we can expose these bad eggs before anything like what happened to your friend can happen again.
Most Pinsiders on this site will let you know if something isn't Kosher. All you have to do is ask.
So lets keep the lines of communication open and expose these rats!
I hope your friend isn't too discouraged. It's a great hobby and mostly made up of great people that just love to talk and play Pinball.