In my experience, as a soon to be mathematics graduate, you really have to research what texts are worth investing in.

As someone who can't focus on pdfs, I buy physical copies of texts. It's a pain to work out what books are worth getting.

Springer has some banger publications. But it also has so pretty shit ones. In my experience, most publishers are like that. I'll never feel bad for pirating a book first to see if it's worth getting.

Fucking paying a week's wage or more for slop - AI or otherwise.