What is your idea of Facebook Extra for 99 $ to Vbulletin? Have you used it? Installed it on your forum and facebook?
Nope, I do not see any reason for using it. vBulletin has FB connect already, that's enough. I do not think that ads and other stuff from your forum integrated into a Facebook app would look good.
Same... It doesn't solve a problem that anyone has (at least not that I see yet). There is no upside to using it as an end-user, and no upside to using it as a site owner. Really doesn't seem like it's useful for anything.