That content it's supposed to be available for everyone, it's good that you are trying to come up with new ideas for the game but that idea will only lead to rage and discomfort among players if it goes live.

FFVII was a single player game, not an MMO, they have to make the new content available to anyone that wants to participate in it, doesn't matter if they are hardcore or casuals, plus, I'm sure you will have to spend gil already in order to get tokens to be able to play in the games, so an entrance fee is highly unlikely but... it's SE we are talking about. :P