yes, you are indeed right. I was of course thinking of the FRA flight that originates in SYD. My bad.

This shows the PER-SIN capacity is now 744+763 daily, so discounting may well be due to capacity availability as well as competition. At some point the QF77 currently operated by 763 will likely go to A330 (when more are delivered/converted to int config) or perhaps be dropped if the single daily 744 is sufficient capacity. But either way, we know QF's plans to retire the 763's from mainline international ops over the coming years.