The true cost of painting the interior of a house.
Painting is NOT just putting paint on the wall.
Many people are surprised at how much time a quality painter takes to properly protect and prepare their homes. (see the yellow part of the pie chart. Or is it more 'Mustard'?)
This includes, moving furniture and other items, wrapping large furniture in plastic, masking all floor edges, protecting floors with drop sheets and boards, sanding and washing trim, vacuuming dust, filling holes and cracks, scraping loose paint, sealing loose edges, undercoating, killing mould, applying stain block ... and more.
So the 'painting' cost breakdown should be around:
30% - Clear, mask, prep, repair
10% Paint walls
10% - Paint ceilings
30% - Paint trim
10% - Materials
10% - GST
As you can see, only half of your dollar is spent on actually dunking the brush in the can.
You can also see that by skimping on the prep stage huge reductions in the quoted price can be achieved. This explains the big differences you sometimes get between one painting quote and another. (And it explains why so many paint jobs fail so quickly.)
More info on the subject of dangerously low quotes here.