It seems like the reasons for the cost have been covered: low sales relative to other electronics, high development costs, gnarly insurance, and the requirement of absolute dependability.
But...
What about skiing is cheap? Why should a beacon, being one of the most important pieces of equipment that a skier can own, be the thing singled out for being expensive?
People have skied in the backcountry for hundreds if not thousands of years without beacons. There's nothing stopping someone from doing that now, but the reason that so many of us have stepped up is that BC safety, especially in high traffic areas, has become a community effort. Strangers depend upon each other to know their shit and respect the lives of the other users while they are out there.
I love the freedom and ability to tune out in skiing. It's great. But I don't want to face the day when I have to make the phone call to a loved one or parent about how their partner or child just died. Especially if it's caused by someone's carelessness or lack of tools. In areas with lots of backcountry travelers, the whole is only as strong as the weakest link, and if that weak link thinks thrice about endangering their life, my life, or my friends lives because they got called out on a message board for breaking that community trust, it makes enough of a difference.
This may be just a thread about the cost of a beacon, but it's also swerved into "I'm not going to buy or use one." Hence the throat jumping.