Following on from JoelT's great post a while back http://www.ozbargain.com.au/node/87343, I was doing some searching and found a pretty good deal on some flights from MEL/SYD to London/Istanbul.
Like JoelT's post this is somewhat long winded but you will not find a cheaper flight. The first leg from MEL/SYD is on Jetstar and the rest of the legs are on Etihad. I tried a number of dates (outside of July) and they are all within $200 of each other so have a play around with dates. The best I could find was as follows:
Edit: Looks like it works for Brisbane as well
10th May - MEL - SIN Dep 11:00 Arr 16:50
Jetstar - $240 with luggage - http://www.kayak.co.uk/#/flights/MEL-SIN/2013-05-10
6 Hour layover in Singapore (note: you can go the day before and spend a night in Singapore if you wish)
10th May - SIN - LHR (via Abu Dhabi) Dep 20:20 Arr 07:20
24th May - IST - MEL (via Abu Dhabi) Dep 14:25 Arr 18:10
$730 AUD on Etihad - http://www.kayak.co.uk/flights/SIN-LHR/2013-05-10/IST-MEL/20…
Total Cost - Approx $970
The price is about the same if you go SIN - IST/LHR - MEL rather than SIN - LHR then IST - MEL
Also the cost of a flight between LHR and IST is around $180.
Hope that makes some sort of sense and helps a few people out, let me know if you have any questions about it.
TO CHANGE THE SEARCH PARAMETERS (AIRPORTS/DATES) IN KAYAK CLICK THE + BUTTON AT THE TOP RIGHT OF THE RESULTS
i might be missing something here. why wouldn't you book the 2 trips together?