Buying one release cover all of them?

I've noticed that there's been a ton of JJOS updates as of the last few months. I've tinkered with each of them, but I was wondering.... if I pay for whatever version is out, and a new one is released, do I have to pay again for the new version? Just curious.

pay once. own all.

Not that any major updates will be coming out... I read on here that they are pretty damn close to the max amount of memory they can use for the OS