Is There a Market for Super Luxury?

The hottest part of the market over the past decade or so has been the really, really top end of the market. One of the interesting things about those buildings is the seemingly bottomless demand on the part of rich people to have enormous numbers of enormous places to live. A friend of mine is an architect who just built a massive house for a very rich client. And he's like, if I ever build a house for myself, it's going to be tiny. Is someone who just downsized one of the hot parts of the market?