EVEN in these days of all-year-round special offers and promotions, January and July remain key sale periods in the retail calendar. So what kind of bargain beds can you expect to find in the sales?

One-off bargains are actually quite rare. These are most likely to be old display models or special clearance lines.

Other, one-off bargains might come in the form of clearance lines produced by manufacturers who, for example, want to use up a discontinued mattress cover.

It might also be possible to pick up odd mattresses and bases for a bargain. It doesn't really matter if the fabrics don't match, as you're going to cover the bed up with sheets and valances when you get it home; but bear in mind some manufacturers' guarantees are invalid if the product is not used with the mattress or base for which it was made.

Buying on credit — especially interest-free credit — enables you to spread the cost of your purchase over months or even years. It's a great facility to enable you to buy a better quality product than you could otherwise afford.

If the credit's not interest free however, you should make sure you know exactly how much more you will be paying and decide if you think the bed's worth the extra.

Only buy a drawer divan if you really need the extra storage space: four drawers can account for about £100 of the purchase price — money better invested in a higher quality mattress if they're not absolutely necessary. The same applies to other features — only go for them if you think they are really beneficial.

The all-year-round discounts that have become a permanent feature of competitive retailing are often supplemented by additional offers, discounts and promotions at key sales periods. Upgrades to the next model quality — king (5ft/150cm) sizes for the price of a standard double, or money off your old bed, traded in — are typical of such offers.

"The best basic rule is to remember that a bed is worth what you pay for it," says Sleep Council consultant Jessica Alexander. "That £1,000 model on sale for just £500 is not a bargain if it's not the right bed for you and if it's not going to give you the support and comfort you need for a good night's sleep."

As the old adage says, you should always buy the best beds and shoes you can, because if you're not in one, you're in the other!