Back in the 80s, I discovered how valuable some of my models had become, and I started selling them. Soon, every model I saw had dollar signs attached to it. My hobby became a business, and soon the fun of it left. I was lucky, finances caused me to have to sell nearly all of my collection, and when I was finally able to get things back together again, I'd discovered the hobby as a hobby again. Today I might occasionally sell a model, but I don't do it for a business. I do some projects for others, but they're done with no money attached. Be careful. There are many that can have enjoyment from both the business and the hobby, but it's way too easy for the business to take over the hobby.