I take my sister up Melbourne's Collins Street, to show her the office where I work. It is at the end of the street where boutiques display shirts whose stripes meet perfectly at the seams, and where Burberry bags outnumber Big Issue vendors. Here, the women's faces look as if they might melt if it started raining heavily, and the men take on a carefully contrived, casual-day-at-work look. Old age almost disappears, apart from a few distinguished old men in suits and mature-aged women who look like they could be running for parliament. People here begin to look like origami, in shirts folded with complicated cuts and pants so sharp you could almost slice a finger on the seams.

I have never been to Paris, so the closest approximation of it I experience is my walk to work every morning. We have lived in Melbourne all our lives, and like parochial young Asian Amish we blink a lot at the things we see. "Look," I say to my little sister, Alison, as we come across the Hermès shop window, "that's a real Birkin bag."

"What's a Birkin bag?" she asks me.

I point to the orange leather item with the lock wrapped in its distinctive tiny leather pouch. "You have to put your name on a list, wait two years and pay $10,000 to get one of these bags. I read about it in the Good Weekend."

"That's stupid."

"Every stitch is hand-stitched. The people who make these bags have to do two-year apprenticeships."

We stand in front of the window to have a closer look. What's in a bag? Stuff you carry around every day: your wallet, your keys, your glasses, your mobile phone, a few band-aids. Lipstick. We wonder why people would want such a bag, why they would wait two years to spend that much money. There is no way we would ever set foot in the store, especially since I'm carrying the fake Gucci bag my brother brought me back from China.

Not that we are strangers to expensive stuff. Growing up, our homes were filled with the things you could buy if you had money. Except that instead of five or six choice shirts in the wardrobe, or three gold chains, we had them en masse: piles of Country Road clothing were always stacked on my friend Nina's couch and dining table. The labels were sorted in bunches and tied with rubber bands, and we sat on the floor with her grandmother, putting the little spare buttons into plastic bags. My friend wasn't interested in sewing, just as I was not particularly interested in my mother's jewellery-making. So we never looked in shop windows and coveted, even though this fashion and jewellery had made our parents their money, and built and furnished our homes.

Once we went to a furniture store to select items for our mock-Georgian mansion and my mother rested her hand on a cream sofa. Her hands were cracked and black from her work, a blackness that penetrated her skin so deeply that no amount of grainy industrial soap could remove it: the black seeped into the cracks of her calluses and the grooves of her fingers and stayed there. If she stopped working for a few weeks, her hands might become clean again, but she never stopped working long enough for that to happen. The salesman saw her hand on the sofa. A look of extreme concern crossed his face. Not concern at how someone could get their hands in such a state, but at how he could protect the creaminess of the sofa from such grot. He didn't realise it was safely indelible on her skin, this blackness.

Because my parents worked so much, we had lots of money when we went to buy the sofa. We were loaded. The furniture-seller made a massive commission that day. Pre-sale and post-sale, he did not treat us differently. It was obvious what sort of people we were, because the furniture shop was in Braybook, home of the Invicta carpet factory. It didn't really matter to him, as long as there was commerce to be conducted. Someone told me once that the best thing about this country is that we don't have clearly delineated classes: a barrister can sound like a bogan; a bank manager can wear trackie dacks in public on Saturdays. It doesn't matter what your hands look like; if you have money to spend, your business is welcome anywhere.

But in those Collins Street stores, I think they would know that people like me only come to stickybeak - or, even worse, to improve our sewing skills. They would see my imported suit and guess that it was not imported from a desirable country. Even my own relatives reject anything from the Motherland with a contemptuous zhongguo zuo de wo bu yao - ‘I don't want anything made in China.' But if we all really meant this, very soon we would see shoeless, naked people walking the streets, their mobile phones and iPods mysteriously gone. Everything seems to come from the Middle Kingdom these days. In Australia, if you are carrying around a white monogrammed Louis Vuitton bag, people automatically assume that it is a fake. Filipino women in Footscray carry them all the time. Barely anyone can tell fake goods from real, unless it's the most garish pimping Rolex, the glue still showing around the edges of its plastic diamonds.

Of course, on Collins Street you don't just get a handbag; you also get to show the world that you can spend $10,000 on accessories without blinking. And this is why my sister and I cannot walk into one of these stores by ourselves. We may have money, but we will never be able to spend it with such carelessness. We will never be able to enjoy a cup of coffee on Lygon Street without thinking that it cost as much as a tin of International Roast, and we will never be able to buy a slice of cake without calculating that for the same price we could have bought three packet mixes. There is always this internal measurement going on inside our brains. Maybe we are cheapskates; but when we know that our labour is mingled with our possessions, we value them. And we also know that some things are grossly overvalued.

So Alison and I stand in front of the shops. Louis Vuitton. Chanel. The bespoke jewellers. We are not there to study the beautiful objects as works of art, but to figure out how they were constructed. The mechanics of it, what shapes had to be cut out, the way the skirt was stitched, the grain of the material. "They have long threads on their bobbins," I explain to Alison. "That's why there are no broken stitches." We watch a woman enter the Hermès store. "Let's see if she buys a Birkin bag!" I say. But Alison reminds me that we'd be waiting a long time to see her walk out with it. About two years, in fact.