I shoot two Dance Academies. One of them I shoot the performance only. Pay 15% commission back to the studio. Parents order prints from my web site (www.auphotography.net). Also do special assignment at rehearsals for $25 plus what ever prints, etc they want.
Second studio, do both Photo Day and Recital. Again 15% back to studio. Parents buy Photo Packages at Photo Day and order Recital from web site.
Tough question. The real question is how much are you worth? If you go for "reasonable" you cheapen your self in your eyes and that of your client.
Figure out if you will be able to make additional sales to performers, if so then charge a lower rate speculating that you'll make up for it in Photo sales. If you can't sell to dancers and their families (boy/girl friends, parents, grandparents, uncles & Aunts) the ask for a higher fee.
Remember you are not just charging for some cheap pictures. You are an artist, a creator, someone with a unique perspective... a professional.