John...no, not appreciably so. Of course there are hundreds of variables on any given project, but the basic building systems are the same, and unit rates don't go up for taller projects, in fact many of them come down. It wouldn't surprise me terribly to find two 40-story towers to be as expensive or even more expensive, than a single tower twice as tall, especially if the larger footprint of the double tower configuration required significantly more land acquisition.