I'm looking into doing something like this on my Patreon with annual subscriptions, wherein you pay for 8 months but get a full year of updates. In this example there would be a 33% discount of money saved. The math/setup of this hasn't been planned out quite yet, however.
And there will continue to be free versions of the game released month(s) after the paid versions are out, though they won't contain any Endurance/Elysium benefits.