How much is a single digit worth?

 How much is your middle finger worth? Is it worth more if someone takes it from you? How much would you pay to keep your middle finger? Is it $900? That seems like a lot of money. But middle fingers are important for many reasons. For example, one of my new life goals -- to possess this xray of my own hand:

Someday, I shall have this fantastic x-ray of my own hand, preserved and captured in this declarative pose. Let the search begin.