One thing to understand about selling art, is that the quality of work is only one, small aspect. The importance of the 'portrait' itself is an aspect. The popularity of the artist, the gallery it's in, etc. Art is more than expression, it's also very political, and a competitive sport. Suggested worth and actual worth, like most things, are entirely subjective and unique to the individual.
Why not? If that's how much he paid for it, that's how much its worth. It's a high quality painting of an important person, so of course it's going to be worth a lot. If Felipe Calderon called you up and asked you to paint a portrait of him, why would you only ask for a few hundred dollars?