I think the owner most likely balked because you point blank asked for a 50% rate increase. When my wife went from "team member" to "management" and moved from hourly to salary, her increase in pay was about 25%, with scaled quarterly raises.

I also know a guy that has been working at a bike shop for going on 12 years now, and he makes around $12 an hour. In California. And he manages 2 days a week.

So it's perhaps less about your estimation of value vs. the owner's, and more your value against the market.