Chinese visas were mentioned. Note that when arriving into Peking/Shanghai from one non-Chinese city and departing to a DIFFERENT non-Chinese city transit with a visa is permitted. Other cities are also included with the time limit varying with the transit city. Three days seems to be "normal".
As CX has multiple daytime flights to eastern Australia, simply ticket from BKK/SGN or TPE for more reasonable fares.
Happy wandering
Fred
The Chinese transit visas can be complex. Depending on what you are doing and what routing you are using, you might need one, or you might not.
If you are in transit to a 3rd country (Taiwan, Hong Kong and Macau count as 3rd countries), and you have a passport issued by a listed country (AU and NZ are both listed), you can get a 72 hour visa on arrival at Shanghai, Jiangsu, Zhejiang, Beijing, Changsha, Chengdu, Chongqing, Dalian, Guangzhou, Guilin, Kunming, Shenyang, Tianjin, Wuhan, Xiamen or Xian. You can not leave that city during the 72 hour period, must arrive/depart from the same city and can not stop elsewhere in mainland China.
SYD-PVG-LHR counts, SYD-PEK-PVG-FRA does not, nor does SYD-CAN-MEL. SYD-PVG-HKG-SYD would also count, even if that HKG is only a transit itself.
If you are doing something like SYD-PEK-PVG-FRA, you'll need a 24 hour transit visa before you depart.
Some cities count the 72 hours from 00:01 the morning after you arrive. Others count it as per flight schedules.