Have you tried Locals? Not a penny a post, but $5/month per board. Can't say there aren't any trolls, but it's definitely more "real" than most social media.
Thanks for the tip, I know nothing about Locals. $5/mo for unlimited use is a different incentive structure.
For spam prevention, what is the advantage of hard currency over a proof-of-work algo? I prefer to manage as few 3rd-party services (and fees!) as possible.