Autographs

I have been searching the internets trying to find a few lines of French written in an autograph by Pauline Viardot about her ideal heaven as a vast library where she could find anything she wanted and could read to her heart's content. I can't remember the exact words (they were in French), but the sentiment has stayed with me for a very long time. I wish I could read them again.

My search did lead me to a website that sells musical autographs, and I did find quite a few of Pauline Viardot's autographs there. I also learned that Viardot was an avid collector of autographs herself. I can't imagine that Viardot was thinking about the monetary value of her autographs. Collecting autographs during the 19th century was all about connection and sentiment. Autographs were meaningful. Now they have monetary value.

It baffles me that monetary value can be assigned to pieces of paper that bear the signatures of people who are no longer living. Do the autographs of people who gave autographs often have a lesser value than the autographs of people who gave fewer autographs? And how is a value determined for musical manuscripts of lesser-known pieces? Do people collect autographs as investments? Do they appreciate?

And why is it that the same autograph seems to be sold by different companies? If you click on the screenshot below you will see that the same letter written by Pauline Viardot is being sold by eBay, AbeBooks, and Biblio, (for different prices). What's with that?