Great! If they feel excluded that will give them more of a reason to sign up. It’s a business forum, 90% of the people on there will happily upgrade their account for $20 a year just for a badge next to their name.

Where has that figure come from? I would like to see some proof of your statistics. The forum isn't even established, I highly doubt anyone would pay $20 to participate in a forum that isn't even active. I would not advise that method at all....

Look at forums that do offer a similar service, webhostingtalk does...I don't think 90% of the forum have a premium membership, hell I don't think even 1% do! And they have more reason to because it's such an established and professional community.

On another note, you can make decent money with forums, I made $1200 last week from adverts, never use adsense or something like that on forums though, rubbish.