Second coats on similar colors are almost never recogicnized as being needed until the coat is applied and has dried. ONLY THEN WILL YOU SEE WHETHER IT NEEDS A SECOND COAT or not. Yes, painters can use a cheaper paint then what you paid for. That is solved by getting your own which, I would charge extra for because I will always have to go get more, or add second coat because home owner tried to skimp on paint, or they got the wrong color etc...
To solidify this response, we have been in business for over 30 years as a painting contractor. We didn't just paint a couple of houses 25 or 30 years ago, we paint approximately 900-1000 painting jobs per year and operate with 40 professional painters doing commercial, residential and industrial painting. This article on behalf of Angie's List is totally asinine! I was under the impression Angie's List was only carrying "legitimate" contractors with established reputations. This article written is primarily referring to bottom feeding, one man band operations, trying to hustle for a paycheck.
Even if you go it alone, specialize to keep your initial investment low. If you do only interior painting, for example, you might get by with one ladder, a few brushes, rollers, basic hand tools and such, for an investment of less than $300. Again, you can add to your tools as you need to (every job is a bit different), and parlay profits into the equipment necessary for exterior painting or working on large commercial properties.
Paint Contractor Co