The part about guitars is definitely true as well. Even Eric Clapton has said that the expensive guitars are only more expensive to maintain but aren't better guitars.
Here's a picture of Stevie Ray Vaughan with his famous, and most favorite "Number 1" guitar:
I would dare to say that this is not a thousand dollar guitar made from the finest parts. :) (In fact, he found it in a pawn shop for cheap before he got famous because it was all he could afford). But listen to him play it and it sounds amazing, just because of the hands it is in.
Of course it's worth hundreds of thousands now, but that's only because it was his guitar.