Would be handy,to get behind the headline, and know what the reasons are for the cost blowouts.
The headline is a result of the Victorian opposition who have a policy of suspending the project if they gain office asking the parliamentary budget office to offer advice about the nominal cost of sections of the rail loop. They reported as asked. https://pbo.vic.gov.au/response/6616
Basically they guess what the cost of building and maintaining the legs of the system will be taking inflation into account but not financing costs and opportunity costs. The expenses include the costs of maintaining rolling stock but I don't think they include income from people who might use it that would defray the costs.
Presumably if it eventually got built a future Liberal government would privatise it. Swapping future income for a lump sum to pay down debt.
I should add that the project will need to treat a huge amount of contaminated soil.
