To be honest, I'm not quite sure if 300 people participate in the current lottery, with nothing to lose, it would seem that they would participate much less if they had to pay. On the other hand, there are currently several prizes, and in the lottery that you are considering is only 1, even if the amount is higher, there is less chance of winning.

Likewise, the only way to know is to test it. If you don't raise enough money in your current lottery to pay the prizes, it's worth a try.

Greetings.