All product ,situation, instructor and market based. If the average income is 15k a year it would be tough to charge $200 a month. But like Dan said it depends on the facility. I run a Crossfit, muay thai, and a small mma programs out of my gym so my martial arts students have access to more than just jiu jitsu they do it all if they so chose. Also Im sure Guys like Marcelo, Caio Terra, etc have earned the right to charge a premium. No set answer.