It's like drugs, prostitution or corruption. Remove the reward and you solve the problem.
Good point of gizzmo, that's what I mean in the first post, to reduce the token price.
Now it can be 100 token for platinum plus the price for top ten, which actually isn't only 10-100 tokens for the 10 teams but it's a good price of 70-80-90 tokens for all the top20- top30 teams some times.