I imagine the Party Pay section would get filled with very populated parties very quickly, which would give people less opportunity to start new ones. I suggest adding an expiration date to Party Pay posts which would help solve this problem.
Mine just hit 23 people and I decided to just edit my post to remove the party link and explain the party was full.
And I just posted my suggestion here:
Implement the practice of auto-pruning any thread with the word, FULL, like a similar thread in Reddit.