$100 seems like a pretty harmless diversion.  But I would add one caveat: Each person purchasing a ticket must take a short exam on mathematics, such as 'If you have a 1 in 10 chance of winning the lottery, what are your percentages of winning?  Now, if you have a 1 in 350,000 chance, what are your percentages?'
If they can pass the exam (open book is fine) then they can play.