If you are going to hire a contractor (professional painter) give a room by room punch list of the fixing of holes small or big, have it identified for the painter to tell you if you need a drywall finisher or if he does this type of work good. Wall repairs can be 3-5 steps to do repairs ( one per day for good drying of patching material and a good sanding) this is what gives you a good paint job only using high quality paint.
I put out a request for bids to several local house painters and quite a few seemed high. One was for over $6000 for painting the exterior of the house with putty fill as necessary, paint included. It was for him and one other guy to do the work. I said, "it's going to take you guys quite a while to get this job done" and he told me that no, they could do it in 2 days. I don't know about you but $1500 a day per painter seems more than just a bit high. I went with someone else and they had several people there for several days working like crazy and did a great job. There are too many scammers.
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.