$20 per notebook is a bit on the expensive side, imo.
A typical flatbed scanner takes about 30 seconds per page. So for a 200 page notebook, you're looking at an hour and 40 minutes that we're saving.
We've figured out a lot of optimizations to make this go way faster, but the point is that we're saving the average person an hour+ of time, and we're making sure the job gets done right :)
We borrow this model from what camera manufacturers like Canon do. When you send something to Canon for repair/exchange, you're in charge of paying for shipping and packing it safely.
Then when the work is done, they ship it back professionally, for free, as part of the service.