If there are differences in cable sound, they are likely to be minute. Why spend so much money for such a tiny if any, benefit?
Well, I'll go first. There are people out there with huge amounts of disposable income. They're capable of falling for the trick of a better speaker cable, and the risers for the cables to go with it. I think there are people that never get to a point of satisfaction with their system, but drop thousands more into it for a 1 to 2% improvement in sound. But, again, they most likely have such money to make those choices to spend their money in such a manner. Sure, just when I think there's a point where I'm getting content with my system, there's a new component that piques my interest, so I do some more swapping in and out. Sure, I'll change components, but the most expensive cables I've ever purchased were probably some Audioquest cables for about $50. The rest of the cable purchase has been very modest in cost. At the end of the day, I realize that what really matters is the music. Taking the time to quiet the mind on the right mix of gear and just enjoy the music.