It is always interesting to see what the market will bear. My personal take is that it would have to have the "A" setting or be one of the close focus models to be worth that much.
But still, when compared to other options, and in light of the retail lens price increases we have seen lately, $200 for one of the better variants is not out of line. I personally
would pay that amount... if I didn't already own too many of them! Maybe that's because I find the 28mm focal length to be just right, a "true normal" on APS-C and a nice wide (but not exaggerated) on film.
Though I have the DA12-14 in my rucksack, I prefer to take a 28mm prime in my pocket when I am traveling lighter. It's the same appeal that the DA15 has for people who already own a zoom that covers that range. (See J's recent thread.)
My usual prime trio is 28 / 43 / 77, but if the DA15 was $200 I'd add it to the list as well.