I think this might be where it comes from for me, too. If you say it’s with x, and I think it’s worth z, I don’t want to insult you or assume you’re trying to scam me by asking for x, but I also don’t want to pay much more than z.

The concept of some mystical “y” living in the middle is lost to me and it’s socially impossible to reach “y” without me calling you a scammer or you calling me cheap, so no deal will be made today.