In the US, (leaving) it is probably a wash---you save sales tax. For tobacco, it is good. For perfume that you buy at department stores, it may be a few cents cheaper plus no sales tax makes it a good deal. If you get your perfume at discount outlets it probably isn't. Agree with Rudi--everything else is a bad deal. Interesting, in South America the duty free shops seem to be denominated in $USD rather than local currency.