Regarding the story on the $1 scanning service, Les Citrome writes:

Everyone needs a book guillotine
Before feeding hundreds of book pages into a sheet-fed scanner (at speeds of 25-40 pages a minute, both sides imaged simultaneously), you will need to liberate the book from its binding. Inexpensive book guillotines are available for this purpose. For hardcover books, it is recommended you tear the covers off first. The book guillotine will quickly remove the spine of the book in one smooth motion, leaving a stack of paper ready to be scanned. If you desire, you can scan the front of the hardcover on a flatbed scanner later.

The scanner
Sheet-fed scanners are commonly available and made by a variety of manufacturers. Basic models allow for 50 sheets to be placed in the hopper, ready to be scanned. Recommended are models that can ultrasonically detect multi-feeds so you can be assured you won't be missing any pages. A higher-end model is illustrated...

To read the complete article, see:Preserving books by destroying them: a foray into digitization of a professional library(onlinelibrary.wiley.com/doi/10.1111/ijcp.12316/full)