Binding and materials consideration

In order to produce a good typographic guide, I was planning to do a metal ring-binding guide book vertically as it is easier for readers to flip the pages. Also, I was decided to print it in double side because it can save more paper. However, as I worked some pages in black&white and colour, they can't be printed in both colour mode at the same time and if I printed it all in colour mode, it would costs a lot of money. Therefore, the easiest way to solve this is to print it in single side so that some pages can be printed in black and white so that I can save more money. The only disadvantage of doing that is need to use quite a lot of paper.