I still remember my math teacher that specifically told us to get a certain version of the textbook, and the version he specified was 1 or 2 editions old. Ended up costing me something like $20 to buy used vs $100 new.

I had a class where the textbook did that. I always would get last year's books to save more than a few coins, but the professor of this class would go through the problems in-class, and they were all different from what was in my book. I went to his office hours to understand why the problems he went over were different from the ones in my book, and he immediately lectured "Ahhhh you must have bought an older book from the bargain bin. I require this year's book in my class and this is how I know who failed to pay for the correct book." The professor was the author of the book, of course. It was at that point it sunk in what a huge grift higher-education was.

I forgot the professor's name, but if you're reading this, fuck you, Dr. Shithead (and all the other Shithead professors who do this).

Incredible that this kind of corruption is tolerated in the credentials industry, most other industries would not tolerate someone making money from customers that way.

Can you imagine going to McDonalds and the guy won’t serve you your drink unless you buy a cup from his side business?

It's awful, and it's shameful but nobody feels shame anymore. The moral bar is "what can I legally get away with taking from the world" now. Nobody is even capable of feeling shame for their actions. It's just "bank account goes up" = "i'm right".

At my community college, the third semester of a three semester general physics course needed a new textbook, even though it covered substantially the same material. The prof explained why: his friends wrote this book. He was the only professor who taught the third course. That really prepared me for the experience once I transferred to a university.

  > failed to pay for the correct book.

The failure here was not the student's. Not the cutie professor, really. It was the dean who allows this who failed.

maybe Dean is a coauthor and is getting part of royalties as well? Happens more often than you think

And thus was the start of a new pirate, and Dr. Shithead lost even more money.

Many of my professors would mention the problem numbers for both the current version, and the previous version, to deal with that specifically.