Is It Fair To Allow People To Enter Multiple Times? Doesn't That Change The Odds For Everyone?

Yes we feel that it is completely fair, people are allowed to purchase multiple tickets in home  lotteries, 649, LottoMax, etc. this should be looked at no differently.  
The number of entries to the prizes still remains the same so the odds remain the same, the individual that puts in and pays for more than one entry does have a better chance but so does someone that buys multiple tickets in any contest or lottery.