Don't ever, ever purchase anything at one of the airport kiosks unless you are in a desperate situation. I bought a pair of headphones once that broke right after the plane touched down for 12 dollars. The food is overpriced, the electronics and medication is overpriced, everything you could possibly have forgotten last-minute is overpriced. Before going to the airport, always bring a pair of headphones, any aspirin or mucinex or whatever you need, all of your chargers, etc. so you aren't stuck buying them at the last second from people who know they're preying on our forgetfulness.
You are a captive audience in the airport. You are correct that these places exploit the unprepared. I try my best to plan everything, but once in a while you are going to forget or need something unexpected. Where these stores really bother me is when flights are delayed and you end up stuck with nothing to do for an unknown amount of time. The passengers cant prepare for it and the airport stores really and truly exploit this.
I agree, things tend to be a bit more expensive at the airport. We spend a lot of time in airports because my husband is from England, so we visit often. It all comes down to preparation. If you're just getting a couple snacks and a drink, it's not too bad. It is just sporting events, concerts, etc. There is no where else to get those items once you're in the airport, so they charge more. I think a lot of times, people also spend that kind of money because they're on holiday (we tend to make exceptions whilst on holiday).
Yep, things certainly are expensive there. It's just business, they know that no one else is going to steal those customers so they can afford to push the price a bit higher. It's the same in most places that are a little bit separated from similar businesses. When there is little to no competition the prices tend to be higher because people will buy what they need even if it's a bit more expensive than it should be.