Just had a quick look and you're probably correct about the direct flights. Ryanair fly Prestwick to Bergamo, so don't know how much this helps.

It's a shame because I have found plenty of availability MXP-DXB-SYD. (It is possible to find the non-stop DXB-SYD leg, but not always).

How does £2700 in F sound? That's a saving of nearly £5,000 for 4 people.

That's an awful lot of frequent flyer miles, especially if booked on Emirates.com