I have come up with a solution as how to do this, but I would like to hear the "professional" opinion on the best way to go about this:
We are setting up the yearly youth ski trip and here is how the payments are set-up:
Deposit: $75 for no activities (leaders & chaperones who chose not to ski or snowboard), $110 for skiing, $125 for snowboarding.
The total cost of the trip is $180 + the deposit, payable in 3 installments stagged between the deposit date and the date of the trip.