If you analyzed the field of medicine about 300 B.C. you would have a very low opinion of doctors, but now the medical profession is highly respected. With cables I'm sure that most of the more expensive offerings are snake oil, but that doesn't mean that there aren't more expensive cables with some legitimate benefits.
Super long speaker cables
Sean, I am curious after one poster mentioned the problem of severe quality loss with a 50 foot speaker cable. I'd like to hear your ideas on what to do in a situation like that.