They look awesome! The best part of it is that it seems like most of the pictures at different levels seem to be taken within a short time of each other, if not nearly simultaneous.
So that is about 55 million dollars a year to completely secure the network and process all transactions. I am not entirely sure how it will scale, but I predict that it will scale logarithmically with the number of transactions, especially considering that mining equipment will become more efficient.
Meanwhile the United States will spend 797 million dollars [1] this year in simply printing and transporting physical currency, not including all the other obvious costs in maintaining a modern currency.