Fair enough. I must say from looking into it more that there seems to be an absurdly wide range of cost estimates being quoted, as well as a lot of mixing up of

Fair enough. I must say from looking into it more that there seems to be an absurdly wide range of cost estimates being quoted, as well as a lot of mixing up of prices and costs, so the figures I quoted are probably bullshit. Edit - I am not sure I agree with you about overbuilding on infrastructure though. A good example of this is the London sewer system by Joseph Bazalgette, that was massively overbuilt to the tune of twice the maximum requirement from what was considered the highest possible population density, just in case. Which was very lucky, given the development of the towerblock 100 years later. http://en.wikipedia.org/wiki/Joseph_Bazalgette http://en.wikipedia.org/wiki/Joseph_Bazalgette