I've seen the videos, and I'm sure it is impressive, but it's still just a glorified version of what we've already seen with the other Iron Man figures. A bit more plastic involved, and new molds and tooling (but that applies to any new Iron Man figure). I'm just not seeing something that should logically cost over twice the cost of a regular Iron Man figure. Of course, logic doesn't feed very strongly into HT's pricing decisions or collectors' buying decisions for that matter.
But you're not just paying for the extra plastic and retooling -- you're also paying for the larger box, the additional transportation costs due to size to get this puppy out of China and closer to you, and you're paying for a unique figure that is unlikely to be reused for anything else which probably has a very low edition size (means the value will soar in a year's time).
All that, plus HT knows only truly dedicated fans will want this and they know those dedicated fans will pony up the extra cash to get it.
Truthfully though, this looks more impressive and seems more difficult to build than the batmobile, which is $150 more.