Is this idea possible without a ton of work?
 

Hi everyone,

I run a forum that has industry professionals mixed in with a ton of people who are just there to learn. This makes it tough to sort out the informed from the uninformed posts. Now that's fine as we'd like everyone to mingle, it's a forum. But we had an idea to create something like a "ghost" forum where only the experts can post in it, but it's cloned to another forum that's public where everyone can openly discuss what these special posters are saying.

I'm guessing this isn't a new idea so I'd really love to be informed on the best way to do what I'd like to do. Thanks everyone.

Make a new usergroup, and a new forum where only users of the new usergroup has access to.
Then you can set the promotion to an amount of posts made by the user.
As soon as the user promotes to the new usergroup, lets say he has 500 posts, he can see the "ghost" forum, and post messages in it.