That's how it works for many courses now. A strategy I thought was fair at my school was - the main text is free, but you can pay for extra practice problems w

That's how it works for many courses now. A strategy I thought was fair at my school was - the main text is free, but you can pay for extra practice problems written by the professor for like $50. That seemed fair to me since I know these adjunct professors aren't making anything for the amount of time they spend.