i came across
Oman Air | First Class while checking out KUL-SIN-LHR from another thread
seems the First class airfare from KUL A330 via Muscat to LHR 787 is selling at Australian $6,870
Edit so from Adelaide J to Syd, F to SIN then J to KUL or Melbourne F/J via SIN - for around $6,100 return
if you fly direct F from Sydney its around $6,500 proving once again that if you Fly More you Pay less
thats a
sum total of about $13,000 ex Australia (flying 6 legs of F - Syd to SIN then KUL to Muscat to LHR
versus the near $18,000 via SIN with QF or Dubai with EK (versus the around $15,000 if you start the trip in NZ)