Hi Mozette, another Pertharian here, been over here six years now. It's interesting you're having a dilemma choosing which city to return to, as my DH (a pom) and I have similar discussions. We have a six month old DS, and for the first time I am missing home and seriously considering starting the process of applying for his spouse visa and getting the ball rolling. He's happy enough to leave the UK BUT he hates Perth. Finds it really soulless, sterile, boring, conservative and one-dimensional (to use just a few of the adjectives he's come out with over the years!) while he loves Melbourne. I can see his point, and I do think that Melbourne is the city more like London. But in my mind, going home would mean family and familiarity, and that's Perth.
I have to say that over the past few years my annual trip home has become more and more expensive. Initially, going home would be like walking around in a sale - everything was half price! But now I cringe just buying a coffee in Perth. The exchange rate is a killer, but the price of everything has noticeably increased. This especially applies to housing. We couldn't afford to buy anywhere desirable in Perth at the moment, so moving back would most likely mean moving in with my mum for some time. Luckily she's in Freo, one of the few areas DH likes, so he could countenance that. The pay-off is that his salary would probably triple moving back to Perth, so we could save relatively easily to buy somewhere decent.
We're happy here at the moment; I love walking down to the high street to buy all our organic vegies, I love the newspapers (massive moan from DH about The West, understandably!), I love the fairs and parks and National Trust, I love the history, the proximity to Europe - I even love the poms themselves, bless them. But what I want for my DS is freedom, space, sunshine, fresh air, that smell in the air after it rains, the bush, the stars, backyard cricket, running around with a dog - everything I had and don't see here. So we will go, in the next couple of years I imagine. I think it will be Perth. DH will just have to whinge, but then he is a pom...