Eligible people pay PBS rates (subsidised, as in the UK: I can't remember the rate but it is broadly similar to the NHS prescription rate, although it can vary from drug to drug). People who are not eligible (which presumably you would not be, for it sounds as if you would be visiting and not seeking treatment in an emergency) pay the full cost, which may or may not be expensive depending on the preparation. You would also need to see a doctor to get the prescription (unless of course the creams are available over-the-counter), for which you would similarly have to pay...

Or are you moving to Australia?

Sorry I didn't make myself clear, yes were moving to Oz. Thankfully my youngest is the only one that has any repeat prescriptions and his skin usually improves in the sun, so we can probably reduce the ammounts after a few weeks.
Thanks for your help
xJo