It's been touted to be the next iconic Sydney landmark to rival the Opera House and Harbour Bridge.
But the cost of constructing the 'Cloud Arch' public artwork project has now blown out from $3.5 million to $11.3 million.
The sculpture is to be constructed near the Queen Victoria Building, and will reach across George Street to the intersection with Park Street.
Changes have had to be made to the design due to technical issues, and subsequently the bill for the project has swelled.
Lord Mayor Clover Moore has said that the number of tourists who flock to the area to see the artwork would result in the construction cost being "repaid many times" over, according to a report by ABC.
"Cloud Arch is the most significant artwork to be built in Australia for decades and will help raise our city's profile on the world stage," she said.
"It will become a symbol for Sydney and a popular drawcard for residents, workers, tourists and visitors."