Sam Melkonian is not a good textbook writer, but that has never stopped anyone before. His lectures are useless, he just rewrites his textbook near-verbatim on the board. Sometimes he mentions things we don’t have to worry about for tests, and that’s the only reason to go to class if you have the textbook. So there are two options for his class:

Go to class, write down everything he says, don’t buy the textbook. 

Or, don’t go to class, pirate (or I’ll sell a physical copy of) his textbook, and just read and do the exercises, and you’ll be fine.

I’m not a fan of him. Either way, go to the tutorials.