Too little information to answer.
Ask yourself these questions:
* What can they get in your community they can't get anywhere else?
* Is your community going to see a value *more* than what the people in the community provide, i.e., are there tools, processes, vetting, moderating work that you do, that provides high value
* Are they going to save significant time, effort, money if they join your community?
If you are able to answer yes to these, then perhaps charging would work.
There are negative consequences too. Would be happy to help over a call.