NWR - Photographers

I wanted to get some ballpark estimates for a family portrait session at a park or beach. There are 8 adults and 5 children. Besides the session I am sure we would get at least 5 8x10s, 5 5x7s although I am SURE we would all want to order more prints than that.

Can you please let me know about how much this type of service would be and how much 8x10 and 5x7 reprints generally run?

Thanks for your help!