I am always amazed that so many fashion/luxury watch/goods outlets are empty of customers and the staff just sitting around. Large airports that I use often, BKK, SIN, HKG, BRS, SYD LHR, I avoid shopping. When travelling back to BKK, I buy my allowance at BKK. Saves having to lug it through the journey from wherever. Travelling back to POM, I get my allowance at the boarding airport and lug it back. (believe me if you are living in POM you need your allowance at a decent price)
At POM I look for local crafts to take back as gifts to my Thai friends (they love em) same recently during my Pacific journeys at HIR, VLI, NAN and TBU. Though I'm most probably paying way over the odds for them. I also avoid book shops at airports too. Prices are more expensive than in the local city in my experience.