John knows that Lindsey wanted to buy his BMW classic E30 M3 for her father for quite some time. John was laid off from his job and needed money, so he was forced to sell it. John sends a letter to Lindsey offering to sell the car for $40,000. Lindsey sends an email to John, saying she needs time to arrange financing. Lindsey offers John $1,000 to keep the offer open for three weeks. John agrees, taking the $1,000. Seven days later, Ronald sees Johns add for the car, and he text John saying he is interested in buying the car and has the cash and can meet later today to purchase the care. John is concerned that if he doesn't sell the car to Ronald now, he may not be interested later. Furthermore, John is worried that Lindsey may never be able to arrange financing. John is afraid he may end up with no buyer at all. John knows you got an A in your business law course, and he comes to you for advice. What do you advise will you give John?

5 points for the first post and 5 points for the reply posts. Please fully explain your answers and support them with examples.

You must have an example to receive the full points. Examples can be real cases, cases from the book, or hypotheticals.