Whether a decent headset is worth the money depends on whether you want to continue flying. If not, then no. If yes, then the cost is less than the cost of a decent GPS.
It would not suprise me if somebody did a headset as good as the Bose, at half the price. Technically it must be easy. The question is whether any existing player is going to bomb the price in a lucrative market. Doing that benefits nobody - except the consumer and he doesn't count.
SB
Do you find the replay useful on airways flights? I find the biggest problem to be not that I failed to hear the word(s) spoken; it tends to be that they told me to go to XXXXX and I don't recognise the intersection name. Or they say something like "direct koksy" and only a "regular" would know that is the KOK VOR. The full name does show in the detailed Flitestar/Jeppview plog and it pays to read those names before the flight... however, if I am given a waypoint that does not lie on the filed route then no amount of playback will clarify it; I have to ask for spelling and then I immediately enter it into the GPS and only then (having zoomed out to perhaps 500nm full-scale to see where the purple line ends) I can see where it is going to take me. Airways ATC don't let you mess around for long enough to play back this kind of stuff, IME. They give you 5-10 seconds, max, before they jump on you.