If you do decide to make it a full-time business, the sky’s the limit. The house flipper/contractor that I worked for billed clients $35 per hour for painting, and paid his best painters perhaps half of that, so there is room for some profit there. Consider the case of Matt Shoup, who started with $100 and went door-to-door, asking neighbors if they needed some painting done, then built a painting business that earns $2.5 million per year!
Can't speak highly enough of the service we received from James and his team. I did my due diligence and met with 3 painters. If I'd have met with James first, I might have skipped the other meetings. He talked me out of some extra work that wouldn't have come out the way i'd envisioned and showed me a packet full of successful projects, happy clients that dated back to the 1970s.