I will give them credit for IB (InfinityBoard) for development, but I hate the way it looks and the way they have laid things out. I would not be willing to pay for it as I don't know anyone that has used it (in fact, that is the first time I ever heard of it).
Just from looking at their prices and they way they have their ordering setup, I would think that they had visited vBulletin.com and took a look and then made theirs

- maybe not, just kinds looks the same, in a way.