I am going to buy myself a Chanel 2.55 by the time I turn 25 in 1½ years' time.

Yes, I am aware that with a starting price of about $4,000, owning one of these is going to set me back by more than a month's pay.

The bag of my dreams - a red lambskin jumbo 2.55 with a silver chain - is currently unavailable in stores. But I would be more than excited to get hold of this season's crackled metallic blue lambskin 2.55 priced at $5,910.

It has been a goal I have been working towards since I began collecting bags about three years ago.

Costing about $300 to $2,000, the 15 designer bags come from a range of labels including Kate Spade, Longchamp, Gucci and Louis Vuitton. My prized collection includes the Marc Jacobs Stam bag I bought as a reward to myself after getting my graduate degree last year, and a Balenciaga City bag paid for with my first bonus.

I have been known to forego taxi rides in favour of the MRT and am willing to pack sandwiches to lunch for a bag.

Unlike It bags that come and go, the 2.55 will be a much-loved accessory for the rest of my life. Whether I'm 23 or 63, I know this is one bag I will be proud to have slung over my shoulder.

While in my 20s, the bag will add a touch of sophistication to flirty floral dresses or simple jeans and a tank top.

In my 30s and 40s, the elegant 2.55 won't look out of place with a wardrobe that I hope would have evolved to include sharp suits and structured dresses.

And in my golden years, I'll be the dignified 'bag lady' known for her signature Chanel handbag.

If a handbag that lasts a lifetime is not reason enough for its hefty price tag, let me break it down even further.

There is one formula that I rely on quite frequently to justify my purchases: the cost-per-wear (CPW) ratio. You divide the price of the item by the number of times you wear it. The smaller the ratio, the more value for money that item is.

Which means by the time I'm 60, the 2.55 would have a really tiny CPW ratio.

Compared to a seasonal bag which will be chucked away once it starts looking dated, doesn't owning a 2.55 make sense?

I am saving my pennies and counting down to the day I'll be able to walk out of the Chanel store a contented girl.

In the meantime, I have another happy problem to contend with - my next big ticket bag purchase after the 2.55. Perhaps another timeless classic, the Hermes Birkin, whose starting price runs into a mind-boggling five digits.

Maybe when I'm 30.

This article was first published in Urban, The Straits Times on Apr 17, 2008.