The guild I belong to has national teachers come and give talks and give classes. We are required to pay the fee which is non-refundable. The last instructor we had gave a class for $35.00 and at a national quilt show the same class was $80-$100. I understand why you are concerned but our bus trips are the same way. They are non-refundable unless you can get someone to take your place. I had to miss a class that I had paid for due to my illness but I knew it was non-refundable and accepted it. You don't want a teacher to show up and then no students.