And of course, if someone thinks the car is overpriced, they can make me a lower offer. That's called negotiating (or haggling!).

Coming straight out and saying 'what's your lowest price' is not negotiation. But perhaps that's how some people do it. That was the point of this post - to try and understand why some people do that. Whether I'm 40% or 5% over the market value of the car is neither here or there!