[amykhar]

Create a usergroup with the permissions that you want your paid members to have.
Change the permissions of your registered usergroup so that they can't see the threads, posts, etc.
In your navbar template, do a conditional to show a link to subscribe to your registered usergroup. After they subscribe, promote them to the new usergroup with access.

Making this work is going to hinge on how good you are with template edits and such so that you make it clear to your users what they need to do to see your content.

I would also edit the template that users see immediately after they register. The screen should inform them that the final step is to pay up.

But, this bit of advice is off topic for this thread. Please post your future questions in the other thread so that others may help you as well.