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.
Wow, I learned so much. Now I know why I got the cost quote I got to do the job right. Being a cook I get it... because you can't just make a meatloaf... you can't just paint a room. You better know what you are doing and the cost of a GREAT job is like the right cut of meat. So, you can look at th finished product and smile & enjoy... great job !!