Y'see, it all began with the Zeiss Conquest. A $400 3-9 from them is aimed squarely at Leupold's Vari-X III. Leupold didn't get where they are by taking challenges like this lying down, so obviously some changes have to be made.
Burris, of course, considers Leupold's movements dangerous to them, so they've got some changes of their own to make. This is about how WWI got started, isn't it?
To get back to the original question, what you pay for in glass is coatings. Knobs are nice, glass can be made better, but the money goes to coatings.
Steve