I have just checked February return to Sydney in Business and it was £4600 from Manchester and £3813 from London, bearing in mind there are 5 flights a day to fill from Heathrow the difference is not totally surprising.
As a regular traveller to the Far east it was always the case CX were more expensive than the MEB3, anecdotally usually over £3000 return to HKG in Business when EK was usually at half of that so again the prices quoted by others don't surprise me.
Some will pay the premium for a direct flight some wont, depends who is paying.