I think it is around 2000USD more expensive. Actually your point is quite valid as if I wanted to upgrade the individual sectors it will definitely cost more.
However I might have to re-plan the AKL sector as I wanted to go with CX from HKG-AKL, but given it is now a 2 class service. Possible to change it to just HKG-SYD/MEL-AKL, but that would mean wasting a coupon.
Need to think....
But thanks for all your help