It is based on how much profit you make. If you don't sell much you don't have the money to pay yourself much. Sell a lot at prices that create a profit then you can pay yourself a bunch

I was wondering about upcoming businesses, to invest myself in and upon passion, I stumbled upon the smoking business and I just needed input on how much I would earn if I were to open my own head shop? Also, how much does it cost to start up a head shop, including products, employees, and building maintainence?