I didn't say that any individual will have 16b? They're supposed to be rare, not everyone is supposed to have them. Also, that's not the only partyhat in the game, you can purchase one for 6B. I mean, realistically, the only way you can get a partyhat is from staking or risk fighting bills unless your ready to slave PVM for 1 year. Rares resemble wealth and I believe that the only way to get such an item is through paying a price.
I don't get why you would want a cosmetic item after 100 tournament wins. Rather have an ags or something pking related as tournaments are pking related.