As usual, Lou addressed an essential point:
ant for him, but never ridden. Likewise, a NOS Bianchi from 1951 might be worth a bunch, but a very well worn Coppi ridden Bianchi in F condition  might be worth a lot more than NOS.
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Not only would that well-worn Bianchi ridden by Coppi (it would have to come with solid-gold verification, btw), be worth FAR more than any anonymous NOS Bianchi of the same sort to most people, it would be far more entertaining as a piece of history than the NOS bike would be.
At least, in the market I'm familiar with.
Bicycles are a lovely combination of tool, art, and entertainment to those of us who love them. I would be wary of ever assigning great value to any one aspect of a bicycle, since each of us values these things a little differently.
But provenance, of various kinds, is certainly a big, big variable in assessing value. Of any kind.
Charles Andrews
Los Angeles