Until we get some more confirmation, I'm not convinced that...

Until we get some more confirmation, I'm not convinced that transport is going to be any cheaper. I don't see unloading locally will be any longer in turnaround time, regardless of traffic. Taking into account a trucks avg speed to NAG, I estimate around 1hr 50mins.
We have to assume, whatever configuration semi is used, would be the same for any company accepting PASS, unless NAG can get conditional approval for A-Doubles. (Competitive advantage) although that would raise other issues as one trailer would have to be dropped outside the zone, and multiple trips in/out then hook up and go.
(I would highly doubt Vicroads would approve A-Doubles in the and around the CDB).

Where we are in a fortunate situation, we have a very low cost base, so we are in a position to negotiate with the final price to be very competitive.

All IMO....