I only used the $4 base already built into the previous example. In that example, the teacher gets $40 total for that hour of training with other BB's. And make no mistake, at the level of BB...the teacher is also getting the opportunity to work on his skills with his advanced students. The learning is mutual at that point.
I don't know about anybody else's teachers, and I don't judge. As for what I think my instructor is worth...I think his time is beyond price. He only asks that one show up and practice. No money. If you don't practice, he'll know and tell you straight up, 'Don't waste my time.' Because he can, he teaches for free, and I don't know how I could compensate him for what I have learned.
As for 'black belt clubs'. Seems to me, that if one has so many students that it becomes appropriate to have a special time for 'bb and above training'...that it shouldn't cost any more. Unless, of course, one is using a space that requires payment for that hour. I think a class of 10 BB's could probably cough up...what $40??...between them for an hour of 'BB training'.
So by your example, if you were one of the 10 BB's in that special class, that an hour of your instructors time, teaching you advanced material, is only worth $4 an hour to you? Wow, what a deal! I can't get group ski lessons for that price. For that matter, I can't even get a Big Mac for that price.
Is that what our instructors are really worth?