Cost of painting interior walls/ceiling

How many square meters of ceiling and wall area is it?

We have just under 153 m² of living space, single-story, with sloping ceilings upstairs. The painter estimated about 450-500 m² of surface to be worked on, approximately.

Then it is advantageous. But take a real look at how it appears without filling and refrain from using wall lamps. And it could also be that the plaster becomes rougher from sanding