If the idea of having a simple bank account is the best way to fit everyone, there's one solution to solve currency rate problems...
... just have a bank account in Euro !!! i'm the only CA member to have one but it could help you, I can be your man.
Concerning preventing payment, maybe some of us, the most reliable of course, can pay by advance for a quantity of tickets and a general organiser can sell them back face value one per one to other people...
... it never gonna be a problem to find someone wanting to buy MB tickets at face value.
I check my bank account and I'm able to pay for maybe 50 tickets if money is required asap... that's a part of the solution !!!!