I'm not telling you to support the patreon. One of the benefits of being a patreon is playing builds of the game early that are buggy and have unfinished content. That's their reward for being a subscriber every month.
With a one time purchase you and everyone else buying the game will receive the beta when it's ready. I don't want to release anything that's buggy or unfinished to the masses, and I'm sure you would be highly disappointed if you downloaded a game and you ran into issue after issue.