Hansard from Vic State Parliament today should be an interesting read:
"All Change at Sunshine..." A bit like Albury 1883 - 1961.
I think if you are building basically just another suburban line which happens to have one of its stations at the airport and solved a long list of other issues at the same time, aka Vancouver, you probably could get away with minimal to no surcharge.
But if you are dumping $15B (I thought it was $5B) into an airport line which has one purpose, then no, the users shall pay but in return they shouldn't be served up the standard X-trap, rather it should be a train suited to the task. ie wide aisles, high back seats, information displays etc.
Thinking some more, $15B (assuming no other benefit to other lines) is grossly over the top and the whole project should be dropped, what person in their right mind thinks this is ok. At $1500 capital per user based on 10mpa, there is a lot more the Feds and State could spend our money on that achieves alot more. As a heads up, the Sydney NWRL $285 capital per user. So based on this sort of ratio, the project needs to be done for less than $3B or forget it. Go build another Metro tunnel or spark the IU lines etc etc.