I saw a house like that for sale on the internet a while back. It had all the bells and whistles too(Solar power,Generator,Everykind of radio,bank vault door). Everything a survivalist could ever want. The only problem was that it was something like $750,000.
It's a heckuva lot cheaper to build one than to buy one. But what you're buying is somebody elses disaster preps anyway. I'd do the emergency power, radio, secret rooms or a bank valut door (walk in gun vault and an excuse to fill it) as well as the emergency water and fuel tanks and I'd have a better perimeter intruder plan. That's where having been an infantry captain would come in handy.