EF-S 17-55 Priced Too High?

I've noticed while perusing different sites and fora that the EF-S 17-55 lens is incredibly expensive for a non-L series Canon lens. A good deal on the lens runs you almost $800, and its retail price tops the $1000 mark. Now, don't get me wrong -- I know the lens is a great piece of glass. But I'm just wondering if it's really worth the money?

The EF-S doesn't have weatherproofing, doesn't fit full frame cameras, and it has a plastic barrel (which to me means it is not as solidly built).

Consulting http://www.the-digital-picture.com/Reviews/Canon-EF-S-17-55mm-f-2.8-IS-USM-Lens-Review.aspx , I realize that the lens is a superb optical performer. But I question the pricing of such a lens in the L series range.

Am I reading too far into the differences? I suppose I probably am, but I appreciate feedback. Hopefully I'm not the only one still in sticker shock.