In yesterday's lunch break, I went on the hunt for a new black dress for an event tonight. Strictly speaking, I don't need a new black dress – the four in my wardrobe are all lovely – but I wanted one, and that's much the same thing.

The usual suspects didn't have quite what I was looking for, so I was partially resigned to having to resort to the old friends in the wardrobe when I passed the newish independent near the market. They've always had lovely stuff in their window, but I'd never got round to going in.

It was boutique, chic and even smelled high-end. I immediately felt underdressed even in my nice work frock. Standing a little taller in my heels, attempting to feel confident, I trailed along a couple of the racks, enjoying the soft fabrics brushing my fingers.

There were gorgeous creations at every turn. I murmured in appreciation of a couple of velvety gowns in subtle but confident shades of racing green and azure; a champagne-coloured 100% cashmere jumper dress made me sigh; there was a burgundy satin miniskirt which caused me a pang of physical longing.

Halfway down one side there was the nearest a little black dress has ever come to perfection.

I took it out carefully and eyed it lustfully. It was plain, because it didn't need to be anything more. It was velvet, of such rich black it practically absorbed light. Scalloped neck; short sleeves; a bodice which would caress the shape of any woman who wore it, highlighting whatever needed to be highlighted; a high waist with a loose skirt falling to somewhere just above the knee. The only detail was a thin lace trim to the hem, sleeves and collar, so subtle it was barely there. I could clearly imagine wearing it, actually picture it so well that I could physically feel the experience – the whisper of the velvet as I moved, the soft kiss of the material on my skin, the flow of the skirt around my legs...

It was a sensual epiphany, holding that dress up to myself.

It was a cold corrective when I fished out the price tag. The dress was only a fiver shy of my monthly rent and utilities combined – and at least my landlord has the grace to use the traditional methods of squeezing money out of me. Abusing my desires, like the dress had, was emotional violence.

Glancing round, I was pleased to see the assistant was busying herself some distance away and wouldn't have noticed the tragic but momentary love affair I'd just been though. I replaced the dress carefully and fled.

I will always remember that dress.

On the other side of the market is a reliable charity shop, in which I found a pretty, if unremarkable, second-hand black dress for £3.50.

One of the other women at this posh event has just complimented me on it, and I've just lied about where I bought it.