Advertisement The NSW government was warned last year that the cost of building its flagship rail line between central Sydney and Parramatta risked ballooning to almost $27 billion â nearly $3 billion more than earlier internal estimates â and opening three years late. The forecast for Metro West was made about eight months ago, before the government committed to an extra station at Pyrmont, which will add hundreds of millions to the final cost of Australiaâs largest transport project. The Metro West rail line will run underground from central Sydney to Westmead. Credit:Nick Moir Confidential documents which contain modelling by Sydney Metro reveal for the first time the estimated cost of the project and that the government has been scrambling to find ways to reduce costs.