Selling to a friend vs. other people

Thank you. Please advise my father who wants to sell a car. His friend wants to buy it from him, but he lives nearby and said: "I know you so please sell it to me for a cheaper price". I listed the post for sale on the internet and there are buyers from other cities but they want discounts as well. The question is, is it better to sell to a friend or to people you don’t know, even for same price.

ב"ה Shalom The Chafetz Chaim in his book "Ahavat Chessed" (Chapter 6) writes that there is a preference to sell to a friend and neighbor before strangers especially if there is no difference in the offered price. All the best