The way I've always thought of stuff like this is to offer a free tier and a paid tier. Free tier gets access to most of the stuff and paid access gets you the premium things. You can also do a cheaper tier and premium tier if you're concerned about operational costs.
I think this model works for SAAS companies, I don't think it can be implemented in a community, because the value is coming with the interactions and connections between people in the long term.
