The process of book scanning is often over-complicated.
This is a step-by-step tutorial at its most basic, using articles found around the house - a cardboard box, a desk lamp, a pane of glass, and a camera on a tripod.
There are many more sophisticated ways of doing it, but the basic principles remain the same.
Here is a picture of the basic set up:
The total cost is probably zero.
Here's a link to the step-by-step tutorial which we found on the "Instructables" site:Bargain Price Book Scanner