Honestly it's all going to be in the prep. Just like painting a car that's the most important step and it's the step that gets skimped on the most. and then it just matters what you are willing to spend, anyone can spray a house but the best are going to clean it, address any mold or moldew, scrape it sand and feather the loose and peeling paint, seal the cracks, then paint it and not get it all over anything else (plants, ground, cars etc). if you plan on staying make sure the person has the time and plans on doing it right.