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.
Adelaide Town Hall
After the official opening in 1866, a campaign began to obtain a pipe organ for the Auditorium. The City's amateur musicians held two concerts which raised ₤120 for the Organ Fund, only to see the money used to settle the outstanding account for the Albert Bells instead. In 1869, the Adelaide Philharmonic Society was formed and the choir staged 25 concerts over the next six years to raise over ₤500 for the Organ Fund. The estimated cost of the organ was ₤1,200 and the Council had promised to contribute ₤600. In 1875 Council ordered an organ from the London manufacturers, William Hill & Son. As a compromise on the cost, the Council decided to have Hill & Son construct the organ so that it could be added to in later years. The total cost came to £2106.16s.9d. The opening concert was held on 2 October 1877 but it wasn't long before a campaign to enlarge the organ by adding solo stops began and this upgrade was completed in 1885. The hydraulic engine was replaced in 1923 by an electric motor but after frequent criticism that it was out of date, clumsy of operation, and needed complete retuning to international standard pitch, the Council eventually voted to replace the original century-old pipe organ in 1989.