In a boost for the perpetually postponed East Coast high speed rail link, this mega-project could actually cost about half what everyone thought.
The Australasian Railway Association has released a new study that says a comparison of international construction costs indicates a railway between Brisbane and Melbourne could be built for $35 million per kilometre.
That gives a pricetag of $63 billion - 45 per cent less than the $114 billion estimate in a feasibility study completed last year.
Association chief executive Brian Nye said prices hadn't come down and the $63 billion cost was a reflection of current international costs.
"These construction costs are why the the project needs to be put onto the global market," he said in a statement.
Mr Nye said for this to proceed, the government needs to make a commitment, then establish a body to oversee the project. Then it needs to be opened to the market.
"High speed rail is proven to entice populations out of capital cities and open up regional areas. The study shows these same benefits are viable for Australia too," he said.
High speed rail has popular appeal.
But it is routinely postponed because of the cost and difficulties of an infrastructure project that would cover three states, one territory and involve five governments.
Greens deputy leader Adam Bandt wants the government to immediately start negotiations with the states to identify a route and reserve the land.
He said this month marked the 50th anniversary of Japan's Shinkansen high speed rail network.
"Australia and Antarctica are the only two continents without high speed rail. If we don't act soon, the penguins will beat us to it," he said in a statement.