Someone may already have said this, but here goes anyway!
I think a number of people would balk at five bucks. BUT... if you sell them for, let's say $3 or two for $5, all you have done is given them the perspective of having more chances to win.
It's kind of a mind game with the pricing, because in reality only one person is going to win anyway. All you are doing is spending more on the tickets (peanuts.)
If I was on the ticket buying end and I knew it was for a mission trip, I might even throw an extra five or ten in the bucket just because.
When we run raffles at our elementary school, people often throw extra cash in.
Good luck!