I think that being required to purchase 50 private lessons in advance is unreasonable and I wouldn't do it. As you point out, many things could happen to prevent you taking those lessons. If you don't find the groups, practice time and monthly socials useful, then you are paying a lot for private lessons. I would look around for another studio or renegociate with the one you're with. Don't think they won't do it, I don't know a studio that doesn't make deals to keep students. I manage a studio - our only package is 'buy 11 private lessons for the price of 10'. The student has a year to use their package. Our privates lessons are $60 to $75 an hour depending on the instructor. No one has to pay in advance. The day they start their package is the day they pay. You are right to question their business practices and don't let them play any emotional games with you. Dancers can become very attached to their instructor and their studio and some studios exploit this.