Originally Posted by serfty

The travel agent you talked to was incorrect. Certainly this used to be the case re higher fare based on purchasing country - search here for "Canada Exception".

From Australia you can make an ex Japan booking ticketed by Qantas online using the oneworld booking tool and having the first segment Qantas marketed and operated - it uses the Japan base fare.

https://www.oneworld.com/round-the-world

I had my Oz based travel agent book an 081- ticketed ex Japan DONE4 last month. Total cost was under AUD9000 (USD6100). They do charge for the service but I'm happy to pay that to avoid Qantas Call Center Roulette.