I had that happen a few times when trying to buy the camper van. One guy was in Ohio and against my own beliefs I told him I wanted it and would send a down payment. he said " No it's yours come get it" I took the day off and said I am on my way and it was then he told me it was sold. Creeps
Nice young female friend, was shopping for a car. Made a deal with a seller, got on a bus then walked 6 blocks in a near snowstorm to arrive on the doorstep where the guy announced it was sold. That was downright dirty.