All hail the changing face of the top-up shop. In these straitened times, it seems people are more willing than ever to mix and match where they pick up their produce – doing a big shop in one supermarket and topping up at another.

A recent survey of 2,000 shoppers found nearly two-thirds of people who use upmarket supermarkets – your Marks, your Waitrose, your Whole Foods – also use budget supermarkets at least once a month. And of those, 69% say they’re using budget supermarkets more often than they did a year ago. A further 17% say they would do so if a discounter were in their area.

“Why pay full price when you can get branded goods a lot cheaper in budget stores?” is a typical comment recorded in the survey, commissioned by Vouchercloud. “I use the budget supermarkets for cereals and bread products mainly as they are 50% cheaper,” says another.

A third respondent adds: “They’re not just cheaper, but also smaller stores with fewer distractions, not loud music. They’re easier to get in and out of faster. Even the check-out system is faster and more efficient than the ‘big four’ supermarkets.” All of which tallies with a recent report that found Lidl offers the fastest shop of the major supermarkets.

The success of the discounters, of course, isn’t just anecdotal. Recent figures from Kantar Worldpanel show the likes of Aldi and Lidl grabbing record market share. “Pressure on household budgets is undoubtedly driving some of the growth at the discounters, but messages about quality are starting to resonate,” said Kantar Worldpanel director Edward Garner.

Indeed, Lidl is beefing up its fresh meat and poultry aisles and venturing into areas such as fine wine. Last Christmas, the discounters enjoyed booming sales of premium-quality products such as champagne, smoked salmon and lobsters – premium-quality products, but at a value price.

And price, of course, is key. Stats from Nielsen this week have revealed that rising food prices are a concern for 22% of UK consumers – ranking as the third-biggest concern overall, behind utility bills and the state of the economy. The more discounters can do to tackle this concern, the greater chance of them taking share off their rivals. And then they might start converting some of those top-up shops into main shops – which will really shake things up.