There is a certain unplanned affinity in Germany for public projects not getting finished on time. And when they are finally finished, they usually cost several times the estimated price.
Stuttgart 21 is one such case. It actually only entails putting the complete train rails and central station of a city into the ground. What on earth could go wrong. Then there is the new airport in Berlin. Everything has already gone wrong there. A satirical German blog even suggested introducing a new grammatical form of future to cater for the day the airport will actually be opened.
And then there is the Elbphilharmonie in Hamburg. Initial costs were estimated at around 100 million Euro, quite a nice sum for a new concert hall with an adjoining hotel and a few flats. Thing is, the price has now gone up to 800 million Euro.
I am sure the taxpayer will be getting some really fine concerts for this. That is, if he is still able to pay the admission fee.