Sorry to say this, but I'm afraid jumping to a paywall model isn't likely to work very well.
Generally I support a developer/modder as I wish to say thank you for the work they have already completed.
Occasionally I support a developer with a regular subscription as it gives me earlier access to updates, however if the amount /level of subscription required to get early updates is high, with lower tiers getting very little benefit, it tends to dissuade me from continuing my subscription.
In all cases, it takes either a very original idea or enough content (that I have become interested/engaged in the story or characters), to get me to start subscribing.
Finally if a developer wants quite a high value per month for a meaningful subscription, that soon adds up to substantial amount per year and given that we all have budgets, you should ask yourself, is what I am producing honestly worth what I am asking per year? whether that's in terms of content quality, quantity or originality, especially in comparison to what other developers are producing.
Whilst I can only give my reasoning with any certainty, others on here have indicated they operate with a similar mindset.
Thats my advice, for what its worth ( if anything )
Good luck with your project.