It's all just a matter of priorities. Some folks think spending over $10,000 on a car is dumb, others see spending more than $500 on a computer, or more than $50 on a video card is stupid. For anyone who thinks that spending $1,500 on a pair of headphones is crazy, the simple fact is that you're not the intended audience.
I don't necessarily trust what I read from so-called 'audiophiles'. Being an 'audiophile' is a little bit like being a 'photographer'. Just because you took one good picture of your dog doesn't mean you're now an expert on all things photographic. The audiophile world is, IMHO, similar. The only way to *know* what "good" stuff sounds like is to listen to the "good" stuff for yourself. You can read hundreds of reviews that describe 'veiled soundstage', or 'low-oxygen connectors', or 'velvet midrange', etc. But it doesn't mean a whole lot if you can't put it into context. The only way to do it is to listen and decide for yourself!
About a year ago, I decided that I wanted a *good* pair of headphones for my office. I exchanged several emails with the folks at headphone.com about this, and with their blessing I ordered about $1,500 worth of headphones and amps from them, knowing that $1,000+ of it would be returned.
I spent several weeks comparing and contrasting a half-dozen of their 'best' headphones. The result? There is a big difference between $100 cans and $500 cans. Try it for yourself. Some people might not be able to tell the difference. And that's cool, buy the $100 pair and be happy. But just as some people enjoy wine, cars, cigars, cheeses, types of underwear, video cards, {whatever!} more than others is why the market supports so many varieties of, well, everything. And at different price points.
FWIW, I ended up keeping a pair of Sennheiser HD-650's because their sound was simply incredible and they were comfortable for long periods of time.