I looked this up and fuck this guy: http://en.wikipedia.org/wiki/Antilia_MumbaiEnigma wrote:2-8a Rutland Gate in London, England, is AFAIK still for sale at $484.51 million.
There is a mansion (20 story building but each level is double height) in Mumbai that is worth $1 billion. If you have the dough I bet you could persuade the current owners to sell it.
It's a 27-floor building that is equivalent in height to 60-story buildings. Acquiring the land was pretty much illegal to begin with, and the helipads are apparently against national defence rules (Indian navy is against the three he built).
Wow, fuck this guy.