How about this post-sale question: "I don't like how it sounds. Are you willing to reverse the deal?"
Fancy this, it's an immaculate component, they buy it of free will, then contact you and ask to refund because it doesn't sound like they imagined!
Of course this was after he had asked the pre-sale question, "Do you think I'll like the sound of it?" I wasn't going to step into that one. I told him he had to make up his mind whether to take the chance and that I would not refund if there was were no mechanical/electronic issues.
He still called to request a refund due to how it sounded. He was slow in paying and tried several times to get the last $10 off. I agree wholeheartedly. Don't deal with a chintzy person. I think he changed his mind about expending the money and was trying to get it back.
Are these people really from planet Earth?
Had another guy want to know the dimensions of the speakers I was selling...because he needed to know where in the house to hide them from his wife! I'm surprised he didn't ask me to recommend hiding places!
I thought, Hey guy, that's YOUR issue; don't bring your dishonesty at home into my life.