Hello my friend @crypto.piotr i am very glad reading your post today as it is talking about one of the most important issue on steemit based contest.

I can testify to this same issue with you because we became friends from your first ever contest and i didn't win the top prize but i was greatly compensated for my effort because i received a lot of reply and exposure on that post and i made some friend too including yourself.

Now like you said earlier it is your opinion which is a good thing because you are a good person and you have a good heart and you think a lot about other people's feelings.

Let me say this we have different reason for organising a contest, people do things different reasons and the fact that we have voalition means we can do whatever we have with our resources.

Hence i will say there is no certain way to distribute reward for a contest but the option you gave above is a very good one but i will make a suggestion that for the sake of long time friendship and to maintain a good relationship with the friends.

Top 5 = 25 steem
Next 20 = 4 steem
Next 25 = 3 steem

Though this might not attract a lot but with the situation of steem its going to be a great turn out. Cheers