Character Economics

So - you've got a character. What are his motivations? WHY is he doing whatever great things that create a story around him?

In other words, what are this characters economics? What currency really matters to this person? (If your first answer is money, think a little longer - is it really money, or is it what the character can do with the money? That's two different issues). And if you're writing in something other than this world, you may even need to figure out the society's economics. What matters to them? What's their currency?

Writing prompt: Take a character sketch, and figure out this person's currency. If the person wants love, what does that do to the story? What if it's honor? Or sex instead of love? Write a scene where the characters currency shows.