I've thought of that too, but the really good deals are gone as far as I know, and even if you got it for only a few thousand it would take a fortune to renovate it and keep it dry. My latest idea was to make a home from an old water tower. They are super strong and you could fill in the legs with walls and make a huge living space. Also if the tank were intact you could use a portion of it as an indoor pool! Some people have actually done it now. My idea preceded those guys by a decade or more.
But yeah, my days of dreaming are over.