Matt and I did it a few years back, but it was cheaper then and, at the time, Annual Passholders received a 50% discount, so it only cost us $50 each. We could have potentially had 10 others with us, but we were the only ones who'd booked for that day, so it really was a VIP tour. The downside of that was that we felt obliged to give our tour guide a hefty tip, although she did protest.
This is the only way to get true FOTL privileges - you're taken through back entrances directly to the rides and attractions, rather than having to join the Express Lines. We did enjoy our day and it was good to see some behind-the-scenes activity, but none of the sound-stages were in use - it would have been nice to have seen some production.
Why Universal? Would they not be interested in one of the WDW backstage tours? Where are you BBBing? MK? What about the Keys To The Kingdom tour? It would be much easier if you were all in the same place.