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.
"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."