Duty-free products aren't the bargain travelling shoppers may believe and confectionery was consistently more costly than in supermarkets, a Consumer NZ study has found.
The watchdog said people would do well to check prices before heading to the airport, with less than a third of items checked cheaper at duty-free than other retailers.
Confectionery was the worst value at the airport chains Aelia Duty Free, JR Duty Free and The Loop Duty Free.
All seven products evaluated were selling for a better price at supermarkets or big box retailers, said Consumer CEO Sue Chetwin.
Among cosmetics, more than half were better priced at other retailers and the same was found for electronics.
Some exceptions were found for companies like tech giant Apple, which do not have much pricing competition in stores.
However the New Zealand Custom Service's $700 personal items limit could mean facing a $195 bill if buying duty free, so customers should check before making big purchases while travelling.
Wine was cheaper or comparatively priced at supermarkets or liquor stores.
You'd pay $7 more to buy a bottle of Brancott Estate sauvignon blanc at a duty-free branch than you would at Countdown, where it usually sells for $13.99.
"If you've got a particular product in mind, it's worth doing an internet search to see which price really constitutes a bargain, before heading to the airport," Chetwin said.
Consumer NZ's investigation found duty-free spirits, particularly liqueurs, were consistently cheaper.
But considering excise duty and GST often add up to half the price of a bottle of vodka, gin or whiskey, consumers might expect to save more than they actually did at duty-free.
On the day of Consumer NZ's price survey, a bottle of Jack Daniels - subject to $21 of alcohol duties and levies at the border - was only $5 cheaper duty-free.
"When you remove alcohol duty and GST from the sticker price, consumers might expect to see more significant savings when they shop duty-free than they get," Chetwin said.
The Commerce Commission warns businesses using the term "duty-free" to ensure customers are not being misled about pricing, something the Fair Trading Act prohibits.
It also advises duty-free stores to "clearly identify" goods not subject to duty.
Consumer NZ found nothing prominent alerting customers to this information in its investigation.
"Shoppers should be informed what is duty-free and what is not," Chetwin said.
The organisation is planning to lodge a complaint with the commission.
"The Fair Trading Act obliges duty-free stores to ensure their prices aren't at risk of misleading or deceiving their customers, whether they are from New Zealand or just in the country for a short holiday.
"While we encourage consumers to do their research before they buy duty-free, the ability of people to do this doesn't release duty-free businesses from their legal fair trading obligations."