Is it essential that you get the 3rd edition? 1st and 2nd are on Library Genesis+ (from 2017 and 2021 respectively)
Otherwise, my university had some deal with Springer that allowed the purchase of a softcover book for 25€ (I think it increased to 50€ later), but also free access for the online edition (though not necessarily the whole book in a single PDF, but each chapter separately). Have you checked for similar deals at your university's library?


