The first thing you have to realize is that there is no pricing theory. I don't care if you are talking about gasoline or the Mona Lisa. No economist has ever come out with a reason why people take a particular price over another. Supply and demand are elements of pricing. If there is only one Leonardo Codex left, it means there is a very limited supply compared to all the autographs by Oprah Winfrey. If there are thousands of people who really believe Leonardo da Vinci was a great scientific mind, that price is going up. There are many Renaissance artists who nobody cares about. Their letters go for very little at auction because there is a lot of supply but little demand. No one can ever be sure why is there is a certain price for something, but supply and demand are definitely important elements.
