Take for example, I charge 1.75 sq foot for 10x10 room with 8 foot ceilings. By my calculations this would cost $175 with floor space sq foot, but with you method, it would cost $576.00 That is outrageous. Of course I didn't subtract the windows and doors, which is another thing that makes no sense. Cutting in around those windows takes more time, then just rolling a wall.
Got two bids so far to paint the interior of a new home. 2,600 sq ft. Was painted with flat cheap paint the first time. The first bid was $17,000.The second bid was $7000. Two coats of paint on ceilings and walls. All doors and closets to be painted too. Still waiting on third painter estimate. I'm wondering if $7000 is too high. This painter has a crew of 5, told me it would take a week. Seems a long time with 5 professionals painting.
"We are very pleased. The bid was mid-range to low (compared to the others). This job was begun the very next day with a crew of 3 - 5. The work (paint, carpet, insulation, cleaning, deck wash and stain) was completed in 5 days - a very fast timeline!! The workers were polite, professional, cleaned all debris. I highly recommend Antonio and his business for any home repair needs. Blessings to them."