How much does the ISS cost in total? (in euros)

Answer

The exact amount is very difficult to estimate, but if you include flights from the Space Shuttle and other spacecraft to the ISS, it comes close to about 100 billion Euros over a period of 30 years.
It also includes a number of preparations and it is assumed that the ISS will be used well beyond 2020.
So far, probably about 70 billion Euro has already been spent.
Europe (ESA) pays about 8 billion Euros in total.
It is not clear what the costs will be in the next 10 years.