I've, ironically, had the best luck lately with the small shops in the airports. They're much more willing to let you test their top-of-the-line headphones than any big box retailer.
Yes, to me, it is worth the slight price premium to reward that convenience.
I guess when people walk into an airport shop looking for headphones, they aren't just window shopping, they absolutely intend to buy a pair because they need it for the flight.
That could quickly change once people get fully accustomed to in-flight wireless: browse the web for a shortlist on the first leg, feign interest at the stopover shop, price-compare and commit on the connecting flight.
The logical consequence would be manufacturer stalls replacing shops in the waiting areas (like a permanent trade fair) and Amazon adding pick-up warehouses to the exits.
Yes, to me, it is worth the slight price premium to reward that convenience.