E.g. HKGx-SYD-MEL is $20 more expensive than HKG-MEL. The ex HKG legs book into T class ... what would the SYD-MEL sector book into? Y? B? Q?
H comes to mind, although I'm certain to be wrong.
ex-NZ PE fares book into Business over the Tasman (where required). So perhaps if the fares look good that is a better starting point?