I tried the QC15s today, and I must say the active noise cancelling is pretty impressive. If you don't want to wear IEM's these headphones do tend to block out an enormous amount of noise. I used my Harmon Kardon AVR 1600 earphone jack out, source was a Pioneer CD Player. The bass was so so, still a bit muddy, mids were hollow, and highs rolled off early.
Waveforms that are more constant, like a jet engine hum are more easily handled by these cans. That being said, I can't think of something to compare the QCs to @ the price point given.
We all know that Bose has Built a brand name, and that plays a large role in maintaining the higher prices. It's also part of the psychology, the customer feels he/she is getting something a lot better, because it is more expensive. ( I think this is the case with Dr. Dre Beats too).
It might be overpriced to you, but I guess it's within market norms because people are buying them. So technically it's not overpriced to the point they are not selling the product. I do use bose speakers with my Harmon Kardon, and have found them fine ( they sound better than the cube speakers put out by Sony, Panasonic, etc.). Just skip the integrated lifestyle system.