My single experience on this front (DFW-CNS-SYD-CHC-DFW) resulted in approximately $200 in taxes for two tickets, plus $30 in fees for booking via an agent.
I believe that taxes depend upon the departure city, so YMMV once Asia is included.
Last edited by Illini_Fan; Oct 11, 2006 at 1:53 pm
Reason: corrected routing (replaced AKL, with CHC)