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.
Babworth House
The estimated cost of the work was from A£30,00040,000. The house was on a grand scale with high quality finishes and it appears that it was not until 1915 that Samuel Hordern and his family took up residence in their new home, called Babworth House. Its style and location were sure marks of a class of commercial entrepreneurs which had established itself as part of the Sydney social elite.