I'd venture a guess that as soon as TED became a little popular, it's value actually went down because a bunch of blow-hards would spend the 8500$ to try and give a sales pitch to the elite caste. When that happens, the elite move on.
As an example - in Toronto there's a thing called 'Granite Club', which's just a big gym with tennis courts etc. The initiation fee is 53,000$ per couple.
That's just to make sure people who actually work for a living can't afford it.
First that TEDx events have little to do with TED. Second the prices for proper events are in the elitist levels of society. It's no surprise when you start to notice the audience members are more famous than the speakers.
hah. Yes, the continued existence of TEDx indicates that the organizers of TED are not aware of just how severely TEDx damages their brand.