I have been involved in about 10 sales. One character has been to most sales and has left an impression on me because he has some rather interesting behavior. He has a rather thick central European accent with a bit of a speech impediment. He comes across as a buffoon by making some goofy comments. However, when you reply to his comments he has a very witty come back. So he skillfully sets you up. His chatter is almost continuous. He does not drive but has a driver. His line the other day was that he would like me to drive him as the other "guy" was starting to be cranky and how much would I charge him. Home Farm Girl suggested that she would pay him to take me. He ran with that comment and teased her as to what kind of woman she was to want to get rid of me.
At my daughter's sale he bought a university text from an art course she took. It turned out that he was very knowledgeable about art. There definitely was another side to him that showed he was no buffoon. He could discuss art with a great deal of authority.
He cruises around your sale with his constant chatter. Then he quickly choses several items, makes his purchase and leaves. He probably attends most garage sales and follows the same pattern of behaviour. I'm sure many of the people in my town will know who I'm talking about. Probably none of us know his name.