A few times I went with a friend to sell truck parts on Facebook. Because buyers can be shady. It was always funny when they brought a big guy too, because sellers can be shady. It was always kind of awkward because it always went perfectly fine. My buddy and his buddy would just restate the set terms and agree, and trade. And me and this other guy are just standing there like, "Well, nice to meet you. I'm really glad I didn't have to fight you over some $200 used leaf springs."