You are providing him business by taking his class. Even if his profit margin is slim, that isn't your problem. A customer is a customer and each customer deserves respect.
I would move on to another LDS that will teach your class. Not all dive shops are created equal so shop around until you find a LDS where the atmosphere and attitude there meets your standards and makes you comfortable.
I would move on to another LDS that will teach your class. Not all dive shops are created equal so shop around until you find a LDS where the atmosphere and attitude there meets your standards and makes you comfortable.