Duty-free shops always remind me of this scene from Seinfeld. I'm in general agreement with George....

Kramer: If anything, we’ll probably get there early. I’ll have a chance to
go to the Duty Free shop.
George: The Duty Free Shop? Duty Free is the biggest sucker deal in retail.
Do you know how much duty is?
Kramer: Duty.
George: Yeah, “duty”. Do you know how much duty is?
Kramer: No, I dunno how much duty is.
George: Duty is nothing. It’s like sales tax…
Kramer: I still like to stop at the duty free shop.