Directory Access for Members Only
You can set your Online Directory so that it can only be viewed by users who have purchased Membership Status.
Go to People / Configuration / Directory / Directory Available to / Members Only.
When you set your Directory to be available to "Members Only" you do NOT need to update contact's Directory Settings on the People / Contacts screen in order to block them from viewing the directory. If they do not have Membership Status, they will not see the Directory.
The system may show that they have Directory Access, but what that is telling you is "If they meet the requirements for membership, then we will give them Directory Access."
If you toggle their access to "NO" and then they purchase a Membership, they will still not be able to see the Directory.
One note, Administrators (contacts who have Administrator Access) will always see the Directory.