Their group is just starting so what I think is there will be no fee for the joiners. But still, I don't see the essence of the group and even all of them with a $5k account on Binance there will be a bad result for the other joiners.
In the end, there will be a sure member that will be rekt. That's what I've heard with most of the trading/signals group. But if this group is about productivity and there will be sets of trading contests, good luck to your group.