Forget designer chic and head off to Primark

Normally such a haven of tranquillity, where I can flit about and spend my entire student loan on pieces of polyester nonsense from the '70s in relative consumer peace, the vintage section of eBay, I discover this week, has had its equilibrium disturbed again.

It has done what it did last year with Tesco frocks and the year before with sequinned shrugs, and turned into a strange parallel universe run by maniacal fashionistas with an inexhaustible Paypal account and a steely glint in their eye.

The culprit this time is a certain spangly gold shift dress, copied from one Jude Law's on/off missus sported a few months ago.

The vital difference, of course, is that Sienna's was Burberry, which in recent years has completely shed its former chavvy associations.

While the one being bought in bulk and snapped up on eBay for three times the shop price is, er, Primark (which hasn't quite).

But this is part of the appeal.

For some, it's in that insufferable naff-is-cool-and-cool-is-naff way the style tribes get their 1 pants in a twist over.

Knickers for a knicker; how can you not love that?

For others, it's as simple as this: Primark is great because it's dirt cheap.

In a fashion climate where you can take a short nap after Neighbours and wake up wondering whether leggings are suddenly out again (the day will come, my dears, just sit tight), it makes good sense to pay next to nothing for things you're going to spend next to no time wearing.

Back home, Mum and I established a tradition of compensating for unsuccessful Brighton shopping trips '“ the kind where everything you like is in only sizes six and 18 and the changing room mirrors make you look like Ann Widdecombe in all that you put on '“ by binge-buying cheap underwear until we felt better again.

It's a flawless plan in theory. The only downfall is that the Primark experience is not one designed to make you feel any of the following: calm, cool, collected, attractive, comfortable, sane or clean.

No, walking into Primark is like walking into a very large, neon-lit Turkish baths'¦except, instead of the hot coals and steam, the heat is provided by middle-aged women in cagoules wrestling over the last shop-soiled white gipsy skirt.

Their brows furrowed in determination, little rivulets of sweat running down their foreheads, shoppers forming an audience and making appreciative noises as one gets the other in a half-nelson and pummels her with a pair of 2.99 stilettos until she yields.

Of course, we all love it. You have to, because to be snobbish about Primark is to be the ultimate cultural killjoy.

The buzz of uncovering a wearable gem amid the jumble-sale-style piles of things, which could be a top, a skirt or a dapper headscarf (and nobody's really sure which), is now as ingrained in our consumer culture as Nicole Richie and polyphonic ringtones.

Therefore, pointing out the dubious quality of an item is tantamount to wearing a Country Casuals two-piece and buying porcelain figures of cats from the back of Sunday supplement magazines.

In other words, you've lost touch with all that is now. Shame on you.

However, with the current eBay madness we can observe the concept has been taken one step further, whereby a bargain is covetable even if it isn't a bargain any more.

Case in point: my dear friend Hannah, who desperately wants the aforementioned gold dress for one of her mysterious Oxford uni parties (this one intriguingly named "Queer Bop", for reasons I haven't entirely been able to fathom).

"I put in a bid of 19, then went to the bar..." she admits.

I shout at her like a gym mistress/sergeant major.

"HANNAH RUTH SMITH. IF YOU WANT THIS DRESS, YOU MUST BE A WOMAN OF STEEL. You lurk, you wait and then, in the last minute, BAM! You pounce. GOT IT?"

The next day, she buys one for 25, and I feel proud of my pupil. Of course, the shop price was only 14, but it seems that's the price you pay for a bargain nowadays . . . let's blame Sienna.