Hi Flumpton! Lucky you, we were in Aus for 2 years, been back in the UK for about 18months now. We were in Melbourne, but we did go to Perth for a visit, beautiful place - lovely people ( I am so jealous).
Painkillers aren't that expensive, I worked in a pharmacy so I did buy everything for cost and they tend to sell brands not generics ie nurofen but not the cheaper brand, if you ask you can usually get the cheaper alternative, I wouldn't worry too much about stocking up.
There are a few things we missed when in Aus, dairy milk choclate tastes different, but you get used to it! I really missed greasy take away food, but now we are back I miss the healthier oz version, so you can't win.
I knew a girl that lived in Perth complained about the lack of clothes shops, but you can always take a plane trip to Melbourne or Sydney if you need. It took me a while to get into Aussie fashion, but now I'm back I really miss the shops, the clothes here seem a bit drab in comparision.
Generally housing, rent, gas, petrol etc are all cheaper. Things from China are a bit cheaper too, clothes, crockery, furniture etc but anything imported costs quite a lot, so p[eople tend to buy Australian goods, also helps the economy!
Sorry to ramble on, not been much help.
So many things I miss, Sushi, gold class cinema, noodle box, sunshine, beaches....any room for me in your suitcase!
Katy