Initially Hubble cost $1.5 billion to build and put into orbit.
Hubble allows scientists to test their hypotheses while still giving people beatiful pictures of the Universe. If this idea, of viewing the Earth,
would have cost $100 million then its still alot because there's no scientific merit.
If you want to see the earth then download
Google Earth, I doubt this cost as much as $100 million, although I
can't find the cost of it on t'internet.
How much is a pen and paper, how much are water colours and a canvas and how much is a block of marble and some chisels. Therefore I think it would
have been the largest amount of money spent on technology to give us, what would essentially be, a piece of technology to create art.