I want to sell an entertainment system for say $1800. I find an interested buyer who comes over and looks at it. He says he will call within 24 hours and let me know if he wants it or now. Just a few hours pass and we agree on a price of $1700 and will make the transaction in 5 days time. 48 hours pass and I am having sellers remorse and want out of the deal and want to keep the entertainment system. What can I do?