[rahimnathwani]

Yes, we're getting closer.

I think what bothers me is that the professor is forcing the student to buy a tool with their own money, when buying that tool is neither expected nor optional. And not cheap.

If access the tool were purchased standalone, rather than being bundled with a book, they might not get away with it. Because the students would (rightly) say that they're already paying tuition, so any systems that are mandatory for them to use should be provided by the university.