With the money I suspect has been exchanged, you are dealing with a different psychology. He likely tries to beat down the money on everything he does. Home Remodeling , going to nit pick and try to get a discount of the amount two MEN agreed on.

It’s all a game to them. I would say 95% of us on this board would have visited the car before and picked it up ourselves, because that is part of the enjoyment of our cars.

Now, if you honestly thought it had an important aspect, such as it wasn’t numbers matching after all, but it was priced as such, then maybe.

Block him, and he should get the message. You may even get a letter from an attorney. Just games they play. Keep in mind, he could be psychopath (tons of them in the upper money strata), so just don’t feed his pathology.

Since you are asking input from the board, as one suggested, post the ad to give more guidance.