I used a Christmas gift card to purchase some adult coloring books. Then, I took my books to an office supply store with a printing area and had them cut the spines off. About $2 per cut. Since all my books were the same size, it could be done with a single cut, saving even more money. They have a massive, guillotine style paper trimmer, with a vise built in and a motor driving the blade. The gentleman doing my cuts has a GF who has him trim her coloring books for her, so he took the least amount of spine. Some of my pages were still in folio format.
I can work on one sheet of paper at a time. I don't worry about messing up the other sheets, and I am not fighting the valley of a paperback book.