People are all sophisticated now. If they shout with loudspeakers, they usually can't sell anything, so many people are watching. Some rural owners don't want others to know that there are old things at home, and they don't want others to know how much they have sold. They usually find a group of rural people or old people to chat with and collect old things for a while before taking them out. No matter how valuable things they see, don't pay a big price, at most dozens of dollars, or the other side's.