For a class I do generally use much cheaper fabric but Best Press or spray starch it before cutting. I will even use less fabric or make a smaller project.
The object is to learn. I don't cut well with others and making a cutting mistake is something I will do. To avoid this I usually get the cutting directions before the class and that is OK with the teachers. After all, the class is learn a technique and not on how to cut material.
I don't feel pressured, am relaxed, and ready to have fun and learn.
ali