Honestly, if you think coming to Australia is going to better way of life financially then you may well be mistaken. If you want financial security you are going to have to put the hours in to get it, the days of overpaid jobs are coming to an end.
The cost of living here is greater than the UK so bear that in mind, it does make a Hugh difference where you live as well. Another thing to bear in mind when moving with kids is the cost of bringing them up here compared to the UK, most of the things you took for granted in the UK you have to pay for here and that applies to a lot of things.
Really need to do your research regarding Australia now and not 10yrs ago before you make the move.
We have lived here nearly 4 years have older grown up kids who made the move with us as well and to be honest would never move back to the UK. Don't get me wrong, we miss family and friends etc. but you have to live your own life.