teaching - Ethics of making students purchase lecture notes

I have a professor who has published his lecture notes in the form of a book. The only way to get access to his lecture notes is to purchase them from an off-campus bookstore. To me, this seems like a highly unethical, if not illegal, practice. Shouldn't students have access to lecture notes as part of the tuition fees that they have paid?

A common question seems to be whether we are actually required to purchase the notes. To clarify, he routinely skips teaching chapters in class and asks them to read them from the notes on our own. So yes, we have to buy the notes if we want to be taught the entire syllabus.

Edit: The notes are different from the textbook. The textbook is not really needed, while the notes are fully needed. I'm seeing people confusing the two and claiming that many professors prescribe their own textbooks for the courses. My question is to whether access to notes should be free and universal for every student in the lecture.