Sarah Sands: Shopping is a science, and I know the perfect formula

If you should find yourself in the chilly, unspoilt, Cameronesque parts of Oxfordshire this weekend you may be puzzled by the colossal volume of cars and coaches veering off at junction 9 of the A40. Trust me, they are not looking for Blenheim. The faces pressed against the fogged up windows are not admiring the peaceful stone villages and pretty church spires. They ignore the Sunday parachutists and gliders in the sky. They are just passing the time before they see the first signpost to Bicester Village retail outlet. This shopping Eden had no mention in Cameron's happiness index, yet for young women, particularly if Chinese, there is no lovelier place on earth.

These are the same women you might have seen huddled in sleeping bags outside H&M last week for the new Lanvin collection. To call them shoppers does not do justice to the intensity of their concentration. They are retail scientists. They have an exquisitely refined feel for market value. Every purchase must have the potential for profit on eBay.

I would be delighted if William and Catherine's four-day wedding celebrations could boost tourism, but it will be hard for them to compete with the Burberry store at Bicester Village at midday on weekends. You would not enter the shop if you valued your life. Young women, cling to the clothes rails as if they were ship's masts, to steady themselves before plunging back into crowds. The wilder the scenes, the more serene are the shop assistants. They look young, and perhaps this is their only experience of retail. After Boot Camp Bicester, they may find Oxford Street strangely quiet.

Bicester Village is not Poundland. It is heavily discounted, but it is not cheap. You might find a dress from Dior, or Yves St Laurent at, say, £600 rather than £2,000. But Bicester has found the perfect market balance: the price for goods that customers are prepared to pay. And the "village" is small enough, an odd little Truman Show-style high street, not to cannibalise the luxury trade. The clothes are not sales goods, although they fall tantalisingly short of the showpieces you would most want. For instance, Smythson is elegantly stocked – except for the obvious Christmas presents of diaries and photograph albums.

This is my Christmas shopping so far: Brooks Brothers for male presents, mainly because this shop is deliciously peaceful. Aubin & Wills for teenagers. The White Company for scented candles. Then I run for it, as the coaches come juddering into the car park. Why do economists keep nagging China to spend more, to help currencies balance? Have they never seen Bicester?

The cost of living creeps up, salaries are as frozen as the winter fields, people feel poorer even before the cold slap of VAT hikes coming in January. High streets are fearful about rises in business rates and lukewarm customers. People are cautious about spending. The pre-sales have the smell of desperation about them. I pass one shop selling both cut-price handbags and carpets. What would Mary Portas make of that? It looks to me like a cry for help.

Yet even if the bad luck of the Irish sweeps through our high streets in January, we can be sure that a shopping bastion will survive in north Oxfordshire. It is not a complicated formula: Burberry + discount = paradise. But it is the secret of customer psychology.

Sarah Sands is deputy editor of the 'London Evening Standard'