I did not say they wouldn't be comparable, in fact I said that the TH X00 would likely get close. I owned a TH 900, never a TH X00 so obviously my post was theoretical as opposed to experience based. As for preferences, well that was not my point, I'm quite sure some people will prefer the TH X00 sound, just like some people will prefer the Grado 325 over say an HD 650. My point was, and remains, from a technical stand point it would be foolish for Fostex to produce a headphone that was the technical equal of the TH 900 for so much less, more than foolish, ludicrous. Now as people have said, preference wise that is a different thing, and I am equally confident that there will be some TH 900 owners who own both but still prefer the TH 900.
If Fostex created this equivalent headphone what will that do to the TH 900, or any headphone they try to release with a much higher retail price? I'm sure for some people they won't care and they will buy the new premium offering anyway, but I would think a great many people would look at a very expensive offering and wonder what they are paying for as the TH X00 suggests it is hype and bling only. If this is the business model Fostex is engaging in all I can say is wow, that is stupid and frankly, it will keep me from buying any new flagship from them again as it seems clear they are going to undercut their customers eventually so I should just wait. That is the take away message I get from this type of arrangement.
And as for price not equaling performance, well I agree there isn't a perfect linear relationship, but I think price does carry a significant effect on quality. That might not always be the case, but more often than not it does matter. The real question is diminishing returns and I certainly am aware of that, but I will not say price has no relationship to the finished product either.