There are suites on the 777 . Other than the shower on the A380 , I prefer the 777. There are only 8 seats and I find tends to be less busy than the A380 service . I wouldn't shun that service and the daytime service to Europe is great

in the screen print, it only shows the Qantas flights with a large fare difference

I am not sure when you purchased your ticket. If the ticket was purchased on or before the 20th January , then the fare rules for the Emirates 1st class A and F fare both state

so the Qantas operated flight is not permitted for that fare. Tickets issued 21st January onwards also allow QF operated flights

In order to book the QF flight , it will be pricing up on a very expensive fare . WHat I suspect it is having to do is refunding the original fare minus the cost of a one way ticket VCE-SYD and then charging a one way 1st class ticket Sydney to Venice and leaving you with the EUR15000 fee to pay. For tickets issued 21 Jan onwards, QF flights can be used. Given that you flew the outbound in January I suspect that you purchased the ticket before the 21st January

What is the fare difference on EK413 or EK419 , which are not in the options shown in the screenprint?

Obviously you're not a frequent flyer or working in a business environment. Suggest you read and learn more here on FT before commenting further. There's nothing unusual about your situation.

Thanks for the replies.
Yes the ticket was purchased back in November.
I travelled the 777 back from Dubai to Sydney (was on the A380 but missed that because of engine problems leaving Venice)
I've looked at trying to change via "schedule" and it appears only F is available on the 0600 flight.
All options via "schedule" try to re-route via Adelaide, Perth, Melbourne
It seems the fare change difference maxes out around 26400 euro total.

All routes via ADL , MEL etc will cause the huge costs since your ticket will not allow travel on QF

Given that Expert Flyer seems show A available on EK413 on the 23rd ( though it could be wrong of course ) , I would suggest phoning Ek reservations on 1300 303 777 and get them to check for availability on the flight you want to take and get them to make the change rather than fighting the EK website

I think a reason why you can't see the later flights (direct ones on EK) in the evening is that this engine displays a certain maximum number of results ordered by departure time. Obviously this needs to be fixed by EK.

Like Dave said, and mentioned earlier, a quick call to EK will have you on the flights you want. When I searched on EF I put VCE-SYD return just so availability shows up as if the ticket is ex-VCE, which is your case.

+1.

From the screenshot it seems that some DXB-VCE flights are a 332 while others are a 77W with suites. In this case, there is a big difference and I would try hard to get on the 77W.

I agree - suites are a different league to skycruisers or F on the 332....