Beware the duty-free shops, because according to a new report, there's every chance they are not the haven for bargains that you think - and you may actually be better off buying online when you get home.
So why are we so vulnerable to these rip offs, and which 'bargains' are actually worth it?
Buying boomsShopping in the airport or ferry terminal is as much a part of the holiday as buying plastic replicas of local landmarks when you get there.
Despite the downturn, we are spending more than ever before we fly. Airport sales have increased 6 percentage points every year for the past four years - the kinds of figures the high street must read and weep.
However, research for The Times newspaper has discovered that the cut price booze and bargain sunglasses may not be all they seem. The newspaper looked at prices across a selection of airports around the world and on board a ferry. They then did a comparison shop online, and a price comparison on the high street.
Airports expensiveIn many cases, the airports did not come off well compared to the internet. The report found Ray-Ban Wayfarer sunglasses for £69.86 online (including delivery). This is a great deal cheaper than the £154.08 price tag in Dubai airport.
Why we shopThe problem is that in the airport it is that much harder to do a price comparison. You can't compare a variety of shops, so shoppers often buy into the idea that they are getting a bargain without checking the claims. However, the advent of smart phones means comparing prices is perfectly possible, and vital if you are to avoid an airport rip off.
Of course, there are those for whom airport shopping is a natural way to relieve the boredom, and for whom getting a bargain is less vital than passing the time. As we are called on to get to the airport earlier and earlier to deal with queues and extra security checks, that's yet more time to kill by browsing the shops.
In the Western world we have lost the ability to do nothing. Psychologists call this the 'manic defence' where we need to be constantly occupied in order to stave off negative emotions. When faced with the choice of shopping or sitting quietly, shopping will always win.
Travellers also have to overcome the cunning marketing strategies employed by the airports - such as putting the shops after all the security checks, so that people rushing through will then find themselves at a loose end in the shops. Some airports even make you actually walk through a shop to get to your gate.
BargainsAt least on the plus side, the canny airport shopper will eventually find some bargains in the departure lounge. The researchers found that perfume was often cheaper. A 50ml bottle of Chanel Coco Madmoiselle eau du parfum, for example, was almost £10 cheaper at Heathrow than the cheapest online shop.
Of course, it goes without saying that all this depends on your duty free shopping not bulging out of your bags and forcing you to pay extra to have your hand luggage put in the hold - at which point it could qualify as the most expensive bargain you have ever indulged in.