Consider purchasing supplies personally to save money. Ask the painter for a bid that separates labor and materials. Then explain that you'll purchase the materials and ask for a list of exactly what will be needed to complete the job. Caulking, for example, is an extra supply commonly used to fill any cracks or damaged areas in your walls -- and one that might be overlooked in an incomplete list.
Climate is another factor to consider. Sunlight, wind, rain and salty weather can all wear out exterior paint. Oil-based paint is durable against wind, rain and temperature changes, but sunlight tends to degrade it. Alkyd paint chalks and sheds very thin layers when it begins to wear. Latex paint is the more durable option for very sun-drenched and relatively dry climate areas. Latex paint with high vinyl content should be avoided, however. Acrylic resin is by far the more durable binder for outdoor latex paint.

Over the past year I have had several jobs given to 2 Angie's list recommendations and 1 not from a recommendation. They all have one thing in common, lack of sufficient and correct preparation to save time, labor, and the fact that they put a person in charge that was a cut corners type of worker. The two from Angie's list sent worker/s back to try touch up problems, but once the job is not prepared correctly in the first place any extra work is like putting a band-aid on a dirty wound.