Question about licensing
 

I'm a bit confused about the licensing agreement for vbulletin so I was hoping someone could help clear this up for me. I'm creating a site that is basically as follows: As an example I'll use the 50 states as my forum topics.

So I'm going to have a drop-down menu on the main page where a user can select his/her state from the list and be directed to that state's particular forum without seeing the other 49 states at all. Basically all of the subforums will have their own unique url and the main forum will be hidden from public view. By doing this, I'm essentially only using one forum with multiple subforums, so I would only need to purchase one license for the forum software, correct? Or am I not understanding this the right way?