Another vote for the Bose A20. They are mid-range, IMO, as far as comfort is concerned but are the best I've worn when it comes to noise cancelling/sound deadening qualities. I have used the QC-15 setup but was never happy with the lack of flexibility and one sided-ness of the mic setup. Also, the noise cancelling is far superior on the A20. I have also used several DC's, the Telex 750 and 850 and have test worn some Sennheisers.

I flown with a lot of older captains who definitely have hearing issue - too many years of jets, props and inadequate hearing protection. A head set is one area that I would not recommend cutting corners on.

And regarding expense. If you want sticker shock, price out a high-quality set of hearing aids. Watched that first hand with a couple of older family members.