Professor charging class cash for magazine
This is a bit subtle in general, but the specific case seems benign unless the professor requires you to buy if from him/her specifically. If you can show that you already have access to it (possibly destructive access, depending on the use - cutting it up) but still must again purchase it then it would be questionable. 

However, note that many professors assign required textbooks that you must purchase. Sometimes, believing that the best book for the course is the one they wrote themselves, you are actually contributing a few dollars to their pocket when you buy it. Noting that a $US100 textbook gives the author(s) around $5 back money probably isn't an important element of their decision. There are some professors who will return there royalties to students in some cases when the student buys a new copy. 

I once wrote a supplementary set of notes for one of my advanced classes. They were required (and referred to daily in class), and cost the students the amount required to duplicate them. I didn't gain from the transaction, nor was I specifically paid to create them. 

It is acceptable, in my view, for a professor to require such a resource. It is less acceptable to require purchase from a specific source from which the professor profits.