Planning fallacy
The Sydney Opera House was expected to be completed in 1963. A scaled-down version opened in 1973, a decade later. The original cost was estimated at $7 million, but its delayed completion led to a cost of $102 million.
Mærsk Mc-Kinney Møller
The Copenhagen Opera House, at a cost of 2.3 billion kroner, is one of the most expensive opera houses ever built, was donated by The A.P. Møller and Chastine Mc-Kinney Møller Foundation. It is situated directly across the harbour from the royal residence, Amalienborg Palace, and within sight of his Maersk headquarters. In the same area, Møller donated Amaliehaven, a park between the Palace and the harbour in the 1980s.