Martin Cassidy BBC Northern Ireland rural affairs correspondent

An average family could make savings of more than £440 a year, just by shopping around for milk.

A survey for BBC Newsline in Northern Ireland has found massive variations in shop prices which could mean a difference of £8 per week for the average household.

In a survey which took in many of the United Kingdom's major cities, Belfast's shops had some of the most expensive and some of the cheapest milk on offer.

A typical family buying two cartons a day could save more than £440

Northern Ireland consumers are being asked to pay a startling array of prices.

Most people pride themselves on being good shoppers, but few people interviewed were aware that prices can vary by as much as 80%.

However, Belfast offers some of the best value around, beating Liverpool, Glasgow and London with an unrivalled 49p for a standard two-litre supermarket pack of semi-skimmed milk.

Birmingham and Manchester shared second place at 58p, while shoppers in Leicester followed closely behind with two-litre packs at 59p.

London is where you might expect to find the most expensive milk, reflecting high rates and transport costs.

But some Belfast shops are almost on a par with London prices at up to £1.10 for a standard two-litre pack.

Belfast and Birmingham both weighed in with prices towards the top end of the survey at £1.09 for two litres.

The survey may make interesting reading for a typical family buying two cartons a day.

The saving from the cheapest to the dearest works out at £1.22 daily, or over £8 per week.

Taken over a year, the average family could save £444, based on current prices.

Even the saving between now and Christmas could be significant for many households.

With just over seven weeks to go, there is still the potential to save £60 on milk.

Plumping for the lowest price milk currently available would generate the cash needed to buy many of the items for a traditional family Christmas dinner.