"but the affordability issue is still a bear. Who of us can spend the money, even if the recordings are easily available, which they're often not?"

The problem is, somebody has to pay for it. The second problem is, the artist has to pay for it too. The third problem is, who would make the decision as to what is included in this "near-definitive" library?

There are a number of sources already available. Netmusic, e-folk music.com, and even iTunes has more than 1 million songs available for download. There are other resources. None of these are "free", but the technology makes it reasonable.

Frankly, it is not very realistic to have such a collection.   You can't walk into a single museum and see all the great works of art.