The survey compared 500 products in the categories perfume, skin care, makeup and sunglasses and found that 87 percent of the items were cheaper to buy online. Only 13 percent of the goods had a lower price in the airport's tax-free store.
In addition, the survey shows that the price differences can be large. On average, the goods in the tax-free store were 38 percent more expensive than the same item online.
But it is possible to make a bargain in the tax-free store. In addition to a few serums, the survey also found some perfumes that were about a third cheaper in the airport's tax-free than online.
Online shopping can usually offer a better price than tax-free. But the only sure way to know if you're making a good purchase is to compare prices before you shop, says Ahmadi.
