Why do some people have to be like this?

Why do some people have to be like this? One minute she would settle for $2000, the next minute she wanted 17k.... They are always ready to take advantage and don't appreciate honesty. The point here is not objective value but reaction. The brooch may well have a higher value and it is her right to have it valued elsewhere and not to sell it right away. The argument here is about the fact that when confronted with a condition of relative edge, too many human beings immediately try to take advantage of it. Something is definitively wrong with the psychological development process.