I think these slow corruption games should limit themselves to max $10-20 membership plan.
Well, I think you a trying to get on the horse from the wrong end. You should not care what their highes tier is. Why should we bother if the creator wants to leave a door open for a righ sheik that wants to spend is oil dollars and fund him with 100.000 bucks a month?
What I care more for is how much I have to pay at least(!) to get the game legally. Contentwise, no creator should take more than 6$ as an entry fee - then you still will pay 72$ a year for a game that has lot less content than an AAA-game. If you want(!) to pay more for it, why not? But "force" them to? Hell no. 6$ sounds so little, I think. But if you wait 4 months for a 10 minute-update... oh my!
And i am not even talking about the Patreon-aspect of just tipping the author and not "selling" a game.
If you would ask me, 2$, maybe 3$ should be the minimum fee per month for getting a full update of the game, maybe one or two months later than it is finished. If a creator asks me for more, I usually only sign in after some months, get the new update and delist. Like in Fashion Business, I did not update for more than a year... and I am not that invested anymore. But if I now enter for 15$, it is ok and will have some contend.
Creators underestimate the power of small money coming in steadily and the customer forgetting his payments.
