I think the reality of having to hand over their money outreaches their desire of ownership of said luxury item. At that point any reason seems justified to change one’s mind.
Buyer needs to be very sure of purchase or needs a bit of consolation that seller isn’t gonna point and laugh right after money handed over.
I get it. Each buyer is different. I try to accommodate and make the experience the best it can be for them; after all they’re also buying a tiny bit of your story with the sale.