Booster's pricing, as you may know, is a sliding scale - the less our children gross, the greater the percentage Booster takes.
In the version of the contract (Services Agreement) between FCPS and Booster Enterprises, Booster takes no more than
50% of gross revenue. (Not including $2K due at sign-up.)
If your PTA/O signed what Booster gave them, probably the top figure is
70% instead as it was at my local elementary school last year.
For the FCPS version, click "Amendment 2" at
http://www.fairfaxcounty.gov/cregister/ContractDetails.aspx?contractNumber=4400003780 and you'll see...
It's probably worth looking over all of the contract. There are a lot of differences between the Service Agreement FCPS signed and what your PTA/O probably signed.
(Keywords: contract negotiation, better deal, fun run cost, no forced arbitration, simultaneous fundraisers, child data security, child data privacy, encryption, COPPA.)