Once you do that, then you can gently show them why their desires will not happen. You have to meet those overpriced sellers where they are and work them towards your position. If you draw a line in the sand and you are worlds apart, all you are doing is yelling at them across a canyon. You have to cross the canyon to their side. You need to lead them back across the canyon.
People can often be like cows.
You can push, poke, and prod them, and they won t budge. Your reason for your way has to be a benefit to them. Once they see how they can benefit, they will follow your thinking. The key is to talk to people in terms of needs and emotional benefits to them. Once you have established the benefits, you can persuade people to do anything.