If I may, the answer to that question is found in the contracts that are entered into between publishers and authors. They divide up the pot, and that would vary on how prominent and important the author is. The prices are set and the education system doesn't have any control over that. The publisher and author divide up the pie.
Evidence of meeting #116 for Industry, Science and Technology in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was content.
A video is available from Parliament.