Thank you to everyone who has entered and upvoted. I have changed my mind and there is no minimum number of entries to win anymore. There is a guaranteed winner and I will probably do another one of these next week.

I now have a lottery with higher payout but it does cost 0.1 steem per ticket at https://steemit.com/contest/@nathan24303/the-steem-lottery-spend-0-1-steem-and-win-5-steem.