I could help you if you can explain easily how to make those calculations.

If you only count the last two entries it's easy but what about those other rules and at least 6 entries?

Perhaps you should make it easier for yourself. See how many join this contest. How many of them comment, upvote and next decide what and if you are willing to pay out a certain amount.
You set rules, most didn't care, you are an investor so it's up to you.

Btw @team-ccc will run for 4 more contests. Payout end of November.
50% of the total amount of the jackpot.