I didnt realize that. I wonder how the later survivors voted off to exile island will be able to catch up on fire tokens. I can't imagine any challenge being as grueling as the firewood trek.
The show actually hasn’t said the amount of Fire tokens is what gets someone back in the game from the Edge if Extinction. I think they might be able to use tokens to obtain an a advantage for the challenge to get back in. That would be my speculation.
In the opening episode they showed a price list on Edge when Natalie got her first note. There are two types of things you can buy with the tokens: Strategic or Luxury.
Under Strategic, for 1 Fire Token you can buy an advantage in the return challenge (max 3), and for 3 Fire Tokens you can buy an Immunity Idol that will be good if you get back in the game.
All of the visible Luxury items cost 1 Fire Token each: Hammock, Pizza, Jar of Peanut Butter, Bottle of Wine, Six Pack of Cold Beer. There may have been more luxury items obscured from the camera.