I’ve got 70-80mb pirated books, I think because of the illustrations. Guess it depends on the book.
Other times a PDF of a book is big because someone scanned it and didn't have trustworthy OCR, so they figured distributing images of text at 1.5 MB per page was better than risking OCR errors.
Discounted Seagates ? /s
You clean up the data after you acquire it, not before.