Primers aren't just diluted paint. They're formulated to establish a solid, even base, seal stains and ensure that the topcoats of paint go on smoothly and bond securely to the surface. "Most homeowners use latex primers, but the pros stick to alcohol and alkyd primers because they'll cover almost anything," says John Weeks, of John the Painter in Mobile, Alabama. Primer can affect the appearance of the topcoat. "It's okay to spot-prime the ceilings but not the walls, because primed spots will show," adds Span.
I disagree with your criteria to hire a painter. A prompt returned call is nice but does not indicate the quality or fairness of the painter. As far as a written estimate, that should be more of a qualifier for the bid versus an evaluation criterion. I'm not sure one would have favorable results by hiring a painter on this basis. As far as the bidding process, change orders should ONLY be used if the customer requests additional scope (PMP 101). Angie's list should consider asking reviewers if/how much they were told to pay compared with the estimate. Unfortunately, there are a lot of contractors that are unethical and need to be accountable.
"Modern paints dry too quickly, and are difficult to brush out," says Dixon, who uses paint additives, such as Floetrol for latex paints and Penetrol for alkyds. "Adding a few ounces per gallon slows drying time and makes the paint more workable," he says. Another problem is bridging. "Latex paints form a skin," says Dixon. "Removing painted tape can tear the skin, resulting in a ragged rather than a sharp line." Lastly, taping takes time. "Learning how to cut in with a brush takes practice, but if you can do it, you'll leave most tapers in the dust," Dixon says. (Cutting in is painting just the surface you want, not the surface adjacent to it — for example, where a wall meets the ceiling.) Although there are mildewcide additives, our pros prefer using bathroom and kitchen paints that have built-in mildew fighters. "These paints will prevent mildew from forming, but they won't kill mildew that's already there," Dixon points out. Because leftover mold spores can live beneath the paint and eventually work their way through to the surface, you should also prep bath and kitchen surfaces. First, wash down the walls with a bleach solution (3/4 cup of bleach per gallon of water) then seal with a stain-blocking primer, such as Zinsser's Bulls Eye 1-2-3 or Kilz's Total One.
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.