Hey Zakaries! Thanks for reaching out! The demo is FREE to play and contains a set amount of scenes at the beginning of the game.
The BETA is updated monthly (sometimes more than once!) with new scenes that are able to share as early access as we produce the game. At the moment, we really need every bit of Patreon support because we have all the artists and voice actors to pay, and the game is entirely self-funded. You can always wait till comes out and just buy it on Steam/itch.io for the best value!