Re:well, that is the question. (Score 1)

There's a book I read called Mining the Sky by John Lewis that makes a good case for the economics of getting building materials from space instead of firing them up the gravity well - the Moon is a bit barren unless we can find water there, but one of the numbers he brings up is that even one of the smaller metallic asteroids (say 1km across) in near earth orbit could contain billions of dollars worth of iron, not to mention the 'trace' amounts of precious metals that would probably also run into the billions.

There's also a lot of silicon up there for building solar satellites, but man, I've played Sim City, I know what trouble beaming power from space can be...