I am friends with a professional hair stylist. She purchases her products from a distributor (middleman) at their retail stores that sell only to licensed professional stylists. The manufacturers of those products say that she cannot sell their products on the Internet, for fear that they will land in discount stores etc. and dilute the value of the brand.
I say that once she buys the products from the retail store, they become her property, and she can do whatever she will with them. Sure, it’s not the greatest idea to sell them at a discount price, but the idea of getting sued by the manufacturer of a product you buy in a retail store because they don’t like what you do with your property seems very illegal to me.