I do think that when people really do HEAR good quality sound they often can be convinced it is "worth it".

The difficulty that I see, especially in regards to quality speakers, is that the laws of physics can be stretch to a great degree but not entirely violated.

Case-in-point, things like Outlaw's new "sound bar" -- it seems to use several good engineering principals to deliver very solid performance to at least 48 hz or so, which is excellent, but that stills about an octave off even a standard piano's range -- http://en.wikipedia.org/wiki/Piano_key_frequencies. In other words people ought to experience a subwoofer in addition this to really hear full range music.

Sadly I cannot recall EVER hearing a subwoofer properly demonstrated at any retail store other than a higher end audio store / home theater specialty showroom.