We are currently building a web application that will help people organise their clubs. As part of this we would like the users of the site to be able to collect payments for their events online. For example, let's say there is a user called John who created an event and the overall cost of the event is $100 and he invites 10 people.
I would like to be able to then charge each person $11 ($1 is an arbitrary fee) for website fee. Somehow, either directly or indirectly John would get $100.
What is the best model to implement this type of arrangement?
Do I charge a flat 10% fee, so John pays $10 to me as a fee? But I don't know that 10 is the upper bound of invites?
Do I somehow (and I don't know this part) create a third party account where the 10 people attending deposit the money into this account and then once ready I will deposit the $100 into John's account?