Economy FOC LHR-HKG = 1293 (Tax)
Economy Zone Fare on CX(New Scheme) LHR-HKG = 1397 (Tax) +450 (Air Fare)

Why is there a difference. Am I missing something?

The same reason you have to pay $1293 for a FREE OF CHARGE ticket.

It's all money for OUR BONUS.

TO OUR BONUS
The Management

I haven't checked but someone said if you book an iJourney return flight the taxes are lower than if you buy two one way etickets.

So if you cancel one sector to rebook after a roster change expect a higher price for the new one way eticket :ugh:

Im not worried about return. I just did this simple experiment for a one way ticked London-Hong Kong. One using FOC and the other the Zone Fare and there is a difference of 100HKD in taxes. To me something fishy is going on FFS