There's not much bait on that hook, but at the risk of putting burley in the water, I'll offer this. Norwood for U12-U18 charge $320 for summer season, which is around the mark for most clubs. There are a number of components that go into the jigsaw puzzle that is fees, but the three big ones are:
Court Hire: The most significant cost of a club. When you consider courts go for $30-40/hr (depends on a number of factors as well as if BSA subsidise the cost too), then with a squad (say two teams) that trains for say 3 hrs per week, then the cost of training is possibly $120/week for say 16 kids (not exact I know), so if the summer season is say 15 weeks, or 18 weeks training, then the court hire per player may be around $135/player for the summer season. That's around 42% of that fee.
BA Registration and Insurance: Let's not forget that fees also pays for registration with BSA and BA, as well as insurance. It would be completely irresponsible if kids were allowed to run around on court, get injured and then not have insurance to cover their medical expenses. Forget exactly how much it is, but this portion is important as players need to play with certainty that if injured they get the medical attention they deserve. I thinks it's around $20/player (TBC), but a crucial part of the fee.
BSA Registration: A fee per team registration goes to the governing body. You need someone to organise the competition, pay refs, do all the admin stuff, coach development, ref development. Don't know the exact current nomination fee, but a portion of that needs to be recovered. I know there are entrance fees as well for games that go to cover game court hire, refs, etc
I think those three portions of the fees would account for the majority of the fees.
There are other overheads like coaching directors and JDO's, but I think you'll be surprised at how little they actually get for the hours they devote to their club.