In every home owners life ... the job of maintaining that home arrises.  How do you decide when to bring in the pros?  First and formost, when your incapable of or unwilling to doing the work. This requires from some DYI persons (some of whom do very good work), to realy evaluate the project at hand. How much time do you have while that livingroom with the high walls and ceilings is torn apart? Are you good with working off a scaffle? Do you understand what it takes to remove popcorn ceilings? Can you patch drywall, roll with an extended pole, sand smooth or match wall texture?  Which product is the correct product for the job and your needs?  Did the guy at the paint store see what your up against? OK, you've asked your self the hard questions now why a GOOD company verses the guy who is cheap and did my friends house.  Quality, reliabilty, and sability.  You can find many good cheap painters out there but will they finish the job? Will they be here next year when the paint peels or to honor the warrenty?  Do they give you a warrenty? We resently estimated a job and we could NOT in good faith warrenty our job due to some products that had previous been applied. When douptful call the pros.  40 plus years and counting!