will i always have to buy every update that comes out?
The version/demo(v0.12) right here on itch is free.
The patreon version is v0.15 at the moment, and patreon is the only official method of getting the most recent version currently. Patreon is mostly to help fund the development of the game more so than "purchase" the game.
That being said, the full game(v1.0) is targeted to launch in December, and will be available for purchase on Itch, and on Steam. If you are looking to purchase the game, it might be best to wait until it is completed and purchase it then.