Ironically, though, despite the abundance of interesting and informative posts this thread has, we still are pretty much at square 1 about why video lenses cost so much.
Volume over unit price
http://gizmodo.com/348768/how-camera-lenses-are-made-in-honor-of-pma-2008
That's a video lens being assembled. While some camera lenses can take a year to make, they're probably still manufactured at a much higher rate than professional video camera lenses.
The Hollywood folks seem to like old MF Nikon lenses a lot, they're doing extreme magnification to go to a huge screen, video really isn't that high a resolution, so it's pretty-much got to be down to (a) lack of vignetting in the optical formula (though that could be taken care of with the flange width and flange to focal plane distance) and (b) market (a rich, low-volume market is good for premium pricing.) Just like newspapers, TV stations don't switch out equipment very often- I imagine Hollywood studios are the same, so you pay a premium up-front and take a longer depreciation schedule for the sake of consistency between projects.
As you can see, lens construction is a long process with skilled labor, that also adds to the price- though I'd expect lots of still camera lenses go through a similar process.
