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!
Vinyl siding is one of the more inexpensive siding materials to have repainted, especially with recent innovations in painting materials. Homeowners will first need to vinyl cleaned and repaired, and any clapboards or vinyl sections that have blown off because of climate conditions will need to be replaced. Painting professionals will apply paint quickly and easily over the vinyl siding, much like an interior paint job. The finish, however, may require extensive work and regular maintenance. Expect to pay between $600 (~250 sq. ft.) and $2,000 (~1,000 sq. ft.), with prices likely increasing for the finish. Changing the finish on your siding is not recommended unless it's completely degraded and worn away by the weather conditions.
Oh, where to begin? Let me start with 'watered down paint'. 25-50% before the material gets to the site? Impossible. You would basically be painting with water at that point. It would be less of a hassle, and cost, to simply use proper material. You would be forced to apply three coats instead of two, as the coverage would be horrible. Whatever cost you think might be saved in materials would be lost in labor. House Painting Arvada Colorado