Season 3 will be $3 each time an update releases. But you''ll get the previous Chapters in season 2. For instance, when Ch. 13 releases, it will include Ch. 12 and Ch. 13 and then when Ch. 14 releases it will include 12, 13 and 14.
It's only fair to my supporters on patreon who pay $3 minimum. Plus, as much as I love to develop it, the game is not free to make. So you'll have to decide if it's worth it to you or not, I hope it is. Cheers!