I think one glaring fact a lot of us are overlooking is the marginal value you get once you cross a certain threshold of cost. How often can you actually attain the accumlative value of a higher dollar purchase. I have the Def Tech 7002's that list for about $2,200 for the pair. Is the B&W 800D or 801 going to sound ten times better? Of course not. Discussing the cost of things is almost silly in this passion of ours because our choices, once we moved beyond in ability to afford more then just entry level products, are not based soley on performance. It's folly to think so. When you start paying 3, 5, and 10+ times a typical decent piece of equipment, you're buying it for pride of ownership. You buy it because you've sat up at night thinking how cool it would be to own it. Seriously, I will likely purchase 800 series speakers in the next 2-3 years or so, not because I expect them to sound 5 let alone 10 times better than my Def Techs, but simply because they're some of the nicest looking speakers I've seen and they stir the passion for this hobby. So I look at it this way... the speaker may cost $24K, but I see it as $5k for speaker, $19k for looks, cool factor, show off factor if you can find a neighbor who cares, and most importantly... pure pride of ownership.
We can discuss frequency curves all day long, but you don't spend 20 grand based on a data chart.