Every week a Guardian Money reader submits a question, and it’s up to you to help him or her out – a selection of the best answers will appear in next Saturday’s paper.
Coming back from a Christmas event in Ireland, I was going to buy a bottle of whiskey for my mum in the airport’s duty-free shop. It was €40 (£34). I checked my phone and was £15 back home in Tesco in London! Is airport duty free always a rip-off? How do they get away with it?
Do you have a problem readers could solve? Email your suggestions to firstname.lastname@example.org or write to us at Money, the Guardian, Kings Place, 90 York Way, London N1 9GU.