I'm sure many people see it as an easy opportunity to make an extra buck on the side. I can imagine if you are the one selling a 5711 or any other in demand Patek you could easily get 10k per watch on the side selling to a grey since he's making a lot more on it. I'm positive there are people doing this and making enough money to pay off their house, create a nice nest egg and buy other luxurious stuff for themselves.