Shopping at airports is for the desperate. Everything is overpriced and generally tacky. Those shops are for when you forget to buy someone a present and are therefore forced to buy something with the name of the city/country you’re in.
However there are exceptions to the rule, and while at a Japanese airport I found a bag of used postage stamps; there were approximately 1000 stamps in a bag for about $5. I like postage stamps because they’re every day objects that most people don’t think too much about, but some of them are quite lovely to look at.