Hi there! Sorry about the delay, been a bit busy lately.
The Early Access is intended to be an alternative way to getting it through Patreon, meaning it will be $20/$5 each update.
I don't think Itch even gives the option of one-time purchase for all future Early Access downloads. The only thing I could do is set the whole project to have a fixed price, giving people continuous Early Access that way. But that would both prevent people from downloading the public version for free and be highly unfair to anyone going the Patreon route. :)