Well, the first thing you need to do is create a separate email address which you will use just for quizzes - then :-
1. Save your quiz as a PDF Document and make sure that it clearly says 'To Pay' (or something similar).
2. Advertise your quiz showing your newly created email address.
3. When you receive an email request, reply and send the quiz as an attachment to the email. Add the person who requested the quiz to your contacts list.
4. Keep a separate list (on Excel) of everyone who has requested a copy.
5. When the quiz is returned with payment - mark the list in 4. as payment received.
6. Once the quiz has closed - you can use the email contacts list in 3. to attach a copy of the answers, winners, how much the quiz raised - and your next quiz.
Hope this helps - and good luck with the fundraising.