I can only speak to my personal experience, but I've found most of the textbook requirements for my OMSCS classes to be available online if I want them, general

I can only speak to my personal experience, but I've found most of the textbook requirements for my OMSCS classes to be available online if I want them, generally for free through the university itself. I've been buying them anyway, because I like to have a paper copy, and because my company is willing to pony up for them. But it's not really a requirement.