Hi Bunbury is a nice place. I worried a lot about how we were going to cope financially but we were easily surviving on one wage similar to yours, as Phil says, there is so much to do when the sun is out most of the time, especially for your childrens ages. I did get dismayed with finding work but I found after 2 months of relentless, confidence busting applying for jobs, it all started to come together!! I've read on here before, for some jobs, that doorstepping works alot and in that line of work I should imagine so.
I didn't find the cost of living high but I know most do. Very simply, how many loaves of bread can you get per hour paid, in both places. We have loads more bread in Oz but that could have had to do with our UK jobs!!
Also, the cost of private schooling divide is not as great as in England so is definitely worth some research,,,
Best of luck