Some interesting comments here. In (very) brief, we have returned to the UK (18 months) after 4 years in Victoria. For me, the most important thing is to be amongst people with whom you have sense of belonging. Australia never presented those feelings to us. We thought about lower wages, grey weather (lived in Melbourne-not entirely sure about that one), different schools for our girls, having to start all over again....
But....it was the best decision ever. Amongst friends, neighbours who talk to each other, access to family, exciting sport, great pubs, cheaper shopping bills, real beer, cheap theatre tickets, trips to Wembley with the children, hearing the singing at Twickenham, Summer music festivals, Europe on your doorstep, kids coming home from school happy, I could go on and on....
Just do it. You will find work, you won't earn as much, sure, but you won't be fleeced as in Oz. Life is different here, but my wife, who is a Kiwi, would not go back to live in Oz. Great experience? Yes. Utopia? No.
Good luck.