It's currently $10 for the month which includes the current version (not future versions) but also access to my other in-progress games (Bottomless Mines Alpha 2 and Arc's BJ Training v2 [w/ Add Ons]).
The Steam and itch.io releases will be one-time payments with all future patches and updates included. If you're interested in trying the game early you can try the Patreon version, otherwise if you're money-cautious I'd suggest waiting for the full release on Steam or itch. Hope that helped! 👍