[Len Ovens]
The big difference is that my cheaper guitars are not
finished as well as
the more costly guitars... things like nut and fret ends not rounded as
nice etc.
It's one thing when the nut or frets aren't too well-rounded, but
other, similar results of sloppy manufacturing can harm the sound of
the instrument, for example when the nut slots housing the strings
aren't perfectly straight. The string will be twisted, lose sustain
and become slightly more inharmonic, and since this additional
inharmonicity will vary along the length of the string, proper
intonation will be impossible to achieve on all frets. Also, friction
of the string in the nut will increase, negatively affecting tuning
performance and stability.
Still, judging from my recent experience with new Fender Strats, I
think that for $500-600 you can get a superb guitar that will play and
sound just as good as a model costing ten times that much. You may
need to examine a few more of the cheaper ones to find a thoroughly
good instrument, but the average quality is already surprisingly good.
Classical guitars seem to be different though, I tried to find an
inexpensive "rare gem" recently but every time I tried the next more
expensive one it did seem to play and sound better. This tendency
didn't stop until the most expensive one I played that day, at $4k.