Frankly though, there are much more important areas right now that could really use some extra money, so I'd rather see folks donate to a good cause, if they don't actually need the paper or kindle book... :)
I've been giving my teaching stipend from university to the Fred Hollow Foundation: https://www.hollows.org/ . They can give sight back to many people that are blind, for around US$25.
Edit: Donated. And reported a bug in their donation process that almost preventing me from being successful.
While you're here---do you have advice on the course vs the book? I'm a person who really prefers to learn via writing rather than via video, but if there's stuff in the course that people who use the book can't really experience...
They cover basically the same material. (Except that the course covers only half the book - the rest is planned for a part 2 course later.)
https://books.apple.com/us/book/deep-learning-for-coders-wit...
[1]: https://www.ebooks.com/en-us/book/210066947/deep-learning-fo...
https://www.amazon.com/Deep-Learning-Coders-fastai-PyTorch/d...
that said: fast.ai also released a draft of the book available here (including the notebooks) https://github.com/fastai/fastbook
edit: if you can afford it, getting the book is a great way to support the authors