As always, each and every car stands( or doesn’t stand) on its own merit.
For sale by private party doesn’t make it a good car, nor does by dealer make it a bad car.
Any expensive old car should be checked out by a 3rd party qualified to do so.
As a dealer myself, with an excellent reputation, I kinda get sick of people throwing a stupid blanket statement like the above out there.
Anybody who personally knows me, wouldn’t question my integrity, why question someone else’s you likely know nothing about.