The concept of paying to be part of a community is not new, you can find many communities that charge more than 5€/month.

You can find some examples here: https://community.circle.so/c/showcase/

We are using Circle for organising it and it costs us money, additionally, it will also take time to organise and moderate the community.

I also believe that paying for something brings more commitment, so this is why we have decided to introduce a small fee for joining the community.