Originally Posted by
PAL62V
It was in response to a suggestion of a cheap J fare to Oz during December which involved a positioning flight to begin in CAI and then ending in WLG, via SYD where a long stopover was allowed. So the ticket really needed to end in WLG to enable the cheaper fare. If I used the multi city and made the second flight SYD-WLG, the price shot up, whereas if the assumption was a flight where the SYD stopover was the MCT, the price was extremely good.
Then it sounds like a fare that didn't allow a long (or perhaps any) stopover in SYD. If it had done, it should have priced properly even on the multi-city approach.
You can test this using any fare which you know allows a stopover. Price it using the different search approaches; you should get the same result.
Of course, with that specific fare that you mention, if it really was that cheap then one option would have been to fly all the way to WLG, and then just fly straight back to SYD. It's only a 3½ hour flight ...