I do this regularly. If the book isn't a rare edition, I've almost gotten over the feeling of guilt in chopping off the spine & running it through the document-feed scanner. I've bought several for the purpose of chop-and-scan; it's how I get personal ebooks of books that don't have, and aren't likely to have, an official ebook edition.
This includes out-of-print gaming books, some religious books, and multi-author books where the permissions likely preclude an authorized e-edition.
If I'm feeling guilty or nostalgic about a particular copy, I keep the book, and if the margins are big enough, I've considered putting a
comb binding on the loose pages. (So far, I've just rubber-banded them & put the books back on a shelf.)