Event with team registration
If you are OK with it being on the honor system (you can always check to be sure each team has a paying member), then create 2 Fee Labels 1) Team $100 2)Team Member $0. The teams will have to be sure that one member checks the Team Fee and the rest check Team Member.

It might make it easier if you check the box "Register Multiple Participants" It is under the Online Registration tab of the Event Setup. Then one team member can register the entire team and be sure that they pay the $100 only/at least once.

Note: This is on the honor system since all team members can select the $0 option. But you can check to be sure that they have paid before the event.