There is a lot to concider when quoting for painting such as
How high are the walls, any vaulted ceilings, are you doing trims and doors,any major repairs to do, how much elbo room is there, who's moving the furniture, paintings how many rooms within this sqft.
To say on average up here 1000 sqft 2 coats walls, one coat doors and trims would run in the nabour hood of 1500 and thats just off the top of my head.