Starting a mushroom buisness?

Seems like everyone now days has a side business of making a little bit of extra money. I would just like a cool hobby that is rewarding, but semi achievable. I like to gold mine, but that is hard when it is either freezing or 100 plus degrees. So I have started gardening, which I find really relaxing. But my you tube searches have led me down a dark path. Mushroom growing... I love to eat mushrooms, but there are all different types that I have never eaten. Also it looks super cool when they grow. So I started to do a little research, and to do a small scale mushroom growing, it is kind expensive. There is a lot more to it than just planting and growing. Here is a video that was really helpful on the costs, and it seems that people all around the world are starting their own high end mushroom farms.