Originally Posted by IAmCatOwned

Given that it is a new method, I think it would be wrong of an LQS to offer a class in the method without requiring students to purchase the book. Once a method becomes very commonplace, it's less of an issue, but you wouldn't even know about the method except for having read that book.

I agree with the poster that says she won't be forced to buy a book for a class if she gets it from the library - however, it would be impractical to teach a class and expect the library to provide copies of the book for all participants. Photocopies would be unacceptable as it is not personal use.