I used to get these fares for about £1700, now they cost £3800 or more if I want to do this. The fare breakdown doesn't show three separate components just two, with economy forced into Y which often costs twice as much as the business class fare for the flights.

The reason I didn't specify the routing was because it is not just this itinerary that worked, I had done ones via Kuala Lumpur, Singapore, and Hong Kong in different orders before.