you have to pay to rent the hall/auditorium
you have to pay the audio/backstage personnel
you have to pay for the costumes
you have to pay for any professional/semi-professional taping of the recital
and so on and so forth

The costs add up, and particularly if your studio isn't in an rich area, a dance studio is more expensive than you can imagine.

-signed a person who used to work at a dance studio