Tom and Griff, again just a guess, but I suspect that in light of current economic conditions and the uneven distribution of wealth, I would define "hi-end" as a complete system costing more than $10K, possibly even less. Hell, most people in this country have a tough time socking bucks away in an IRA or 401(k). In those cases, a family that can't even save for retirement would be absolutely nuts to drop even $1K on an audio system. IMHO.
Tom, you make a good point about digital and hi-rez downloads. But what about the cost of the rest of the system, e.g., pre, amp and speakers? Sure, low-fi or mid-fi might cost $5K or less, but here again, how many families can even afford that?
I realize that I am asking more questions than giving opinions, but when one looks at the amount of income the average family unit earns, it's a wonder how they even get by. So if making the mortgage payment and buying food is tough, how the hell would such a family go about dropping $5K, $4 or less on a music systme?
So yes, I suspect that the number of serious audiophile who wind up dropping $$ into audio systems could be low, perhaps 100,000 if not less. IMHO