Let me tell you why we decided fixed price was a poor decision and opted to split variable and largely fixed costs in our fee structure. While I cede it certainly appears easy and direct, it is also a vehicle to increase revenue and margin when applied to items that are not alike.
For exmple, let's take Junior Academy as a talking point. This is typically comprised of U8 - U12 age groups and covers two major partitions in player development (7v7 and 9v9)
U8-U10 operate on smaller fields with single referee. The variable costs are less all around (league, tournament and referee).
U11-U12 jumps to three (3) man ref crew and while rosters do increase (by two) this does not fully offset the individual cost increase. League entry and Tourament costs rise over these age groups in addition to referees.
What does this all mean? Naturally U8-U10 pay more than they should or U11 - U12 pay less or a little bit of both. Or both pay more/less depending on other club costs and motive.
Reminds me of a recent example where I was over at our futsal location talking to the owner, and watching 7-8 Varsity aged volleyball girls training with 2-3 coaches in an entire gym in prime location. Knowing the cost of the facilities (in prime time and location) and player to coach ratio, I mused out loud to the owner that they must be paying a lot of cash to support that setup. He replied "Should have been here an hour ago, the 40+ 10-12 year olds are paying it."
Next problem with fixed price is variable offsets like team fundraising, donations, and club sponsors. It is not uncommon for teams to offset many of the variable costs with sponsorship or fundraising (raising thousands). Even at a club level we attract sponsors and return funds directly to our membership through uniform items and scholarships to directly reduce their burden (on additional cost). I'd be quite honestly shocked if we have more than 5% that didn't cover some part, or all of their variable/team costs.
satus quod perago validus - start and finish strong