Candid sports pic pricing for school

[ldabney]

Hello, I'm wondering if someone can give me some insight into what to charge for taking candid sports photos for a private middle school. I'm used to group/individual sports package pricing for schools. I'm not sure how to go about charging for my time @ games. The school wants the pics for it's own use plus it wants the parents to be able to buy them if they want. I have a way to sell prints to parents online. My main question is, what do I charge for my time spent @ games? Thanks for your help!

Lesli