I am a huge advocate in that department. Check out my thread I started in the portable forums titled "Why does the AK380 cost 4 thousand dollars". From a broader perspective: In general music is subjective and "opinion" based. If someone released a computer with the same specs and build quality as another but charged thousands more and used clever marketing, you'd still have most people (especially the smarter people) not buying it because they'd get more or the same performance and save thousands of dollars by spending less.
I think with audio its a lot harder, because its not usually black and white. (although as a side note, things like DAPs have technical specs and can be more easily compared.. iRiver is exploiting people IMO and I am in the process of reviewing the 380)
Anyway my point is.. high end headphones are only becoming more and more popular so demand is going up, also the economy shows that everything becomes more expensive over time anyway. I think the best thing we can do as consumers is to not be afraid to talk about this stuff and to also really be a lot more harsh on companies who put a huge price tag on their products and expect us to just buy it and pretend its perfect or worth the money. If you look at the headphones people are charging $4000 or more for, they are actually generally less well regarded than headphones like the HD800. I think that means a lot more than we think. We should give more praise to companies like Sennheiser, not for making less expensive flagships but for actually giving us something equivalent (or better) to what they charge.
I could talk about this all day, but this is more of an impressions thread than anything (although I think the belief that pricing shouldn't ever be discussed is harmful to us consumers). If we are vocal about all of our issues (including overpricing) while being constructive and not whiny then we will all benefit from that.