Size starts the price, but it does not finish it
Two homes with the same floor area can have very different wall height, trim, porches, and repair needs.
Prep can take more time than paint
Washing, scraping, sanding, patching, caulk, masking, and primer all add labor and material.
Color changes affect coats
A dark-to-light change or a bright new color may need more coats or a special base.
Access changes the setup
Stairs, high walls, steep ground, pools, tight side yards, and roof lines can slow the work.
A written visit gives the best answer
Photos help with planning. A site visit lets the painter see the true condition and give a clear scope.
What to do next
List each wall, room, trim part, and repair. A full list makes price talks much clearer.