I know this is a horrible option and most likely not what you had in mind, but there is always the option to cut open the spine of the book and use a normal fla

I know this is a horrible option and most likely not what you had in mind, but there is always the option to cut open the spine of the book and use a normal flatbed scanner. Many commercial digitalization services use this approach AFAIK. Other than that, have you checked your local library if they have a book scanner? No need to buy your own ...