Shop N Save, with 50 outlets, and Giant Hypermarket, with six outlets, have a policy of ensuring that the prices of the items they carry are the same regardless of whether the shop is in town or in the HDB heartland.

On May 2, the Consumers Association of Singapore (Case) reported that supermarket chains here, with the exception of the 80-outlet NTUC FairPrice, did not have a uniform price policy.

A Giant Hypermarket spokesman told The Straits Times that this was not so: 'We have always had a one-price policy at all hypermarkets.'

The exceptions were when a store had 'specific promotions on selected items'.

But Case was right when it came to the Cold Storage and Sheng Siong chains.

At the Cold Storage outlets in Hougang and Siglap, a 10kg bag of the Royal Umbrella brand of rice cost $26.80. The same bag cost $27.60 at its Orchard and Guthrie House outlets.

Likewise, Sheng Siong outlets in Tanjong Katong and Tekka Mall charged 25 cents more for a 75g Nissin Cup Noodle than its outlet in Bedok North.

The reason for the different prices: varied rents, renovation and operational costs.

Sheng Siong spokesman Wong Heng San said that the chain paid about 15 per cent more rent per square foot and 10 per cent more in renovations for its higher-end outlets in town centres or near MRT stations.

'Rental costs make up the bulk of the difference. Some stores are also more elaborately fitted than others, so costs differ,' he said. He gave the example of the vertical chilling shelves added to the Sheng Siong outlet in Tekka Mall.

Cold Storage cited higher rents and operational costs in city outlets as the reason for the higher prices there. These included outlets in Takashimaya, Centrepoint and Guthrie House.

Said a Cold Storage spokesman: 'Our stores can have different operational costs because we cater to a wider group of consumers with different lifestyle requirements, so they are outfitted differently. Some have more products and services, which all add up to higher costs.'

An example is its Great World City outlet, which has self-scanning checkout counters. The supermarket chain's ongoing revamp of its stores also includes the installation of touch screens, which provide cooking tips, in some stores.

When contacted, Case executive director Seah Seng Choon said that only NTUC FairPrice had told the consumer watchdog of its uniform pricing.

'The other supermarkets did not inform us about it. Since they have disclosed it now, we will inform all consumers,' he added.

He said that having different prices for the same items was not illegal, but supermarkets should be transparent and inform consumers about why its outlets had different pricing policies.

Nine out of 20 consumers whom The Straits Times spoke to did not know that prices varied among outlets within the same chain.

Said police officer Sarfrazul Ameen, 40, who shops for groceries at least five times a month: 'These companies are already making a profit and should standardise their costs across the outlets...Once costs are defrayed, prices should revert to a similar level as the other outlets.'

Others thought the higher prices were reasonable. 'I am paying for the convenience. I can choose to buy my groceries from elsewhere,' said Ms Michelle Tessensohn., 34, who is self-employed.

limjess@sph.com.sg

ADDITIONAL REPORTING BY HE ZONGYING AND DARYL TAN