I am sorry to hear about your situation. However, why would you front anyone so much money, whether the person is an instructor of dance, a house contractor, a personal trainer, a yoga instructor, a karate teacher, telephone solicitor, etc? Even many lawyers I know do not ask for retainers of this magnitude in ordinary cases. I don't believe that this type of situation is exclusively within the domain of dance studios and teachers. There also is a point when common sense should prevail when considering how much money to pay upfront for lessons, etc. In my opinion, pay as you go should be the rule of thumb or pay a modest amount upfront such that it all would be applied within 3 months at most. Again, I am sorry that this happened to you.