Britons on self-catering trips abroad should shun most resort shops and head for out-of-town supermarkets to get the lowest prices, according to a survey.
Basic provisions for a one-week family holiday in the Portuguese Algarve, for example, are 48% more expensive at a resort mini-market than at a supermarket, the survey by Post Office Travel Money and holiday company Cosmos showed.
Those able to get to supermarkets would also get better value in Lanzarote, Crete, Minorca, Majorca and Limassol in Cyprus.
Including items such as bread, milk and breakfast cereals, supermarket costs in the Algarve were just £56 for one week, but as much as £83 at an in-resort mini-market.
The next best-value supermarket prices (£59) were to be found on Spain's Costa Blanca, which was one of the few destinations surveyed where resort prices were better value than supermarket ones.
The biggest disparity was in Majorca, where the provisions cost £86 in supermarkets but were as much as £133 - or 53% more - in resort shops.
Of the destinations in the survey, Limassol had the highest supermarket prices, with the provisions costing £94.
Andrew Brown, of Post Office Travel Money, said: "Self-catering can be a great way to save money on holiday but the wide price variations between resorts makes it important to do some homework before booking.
"Our research shows that well over half of families bust their holiday budget by hundreds of pounds and food shopping is one of the main reasons why."