Need some spending money? How about selling your soul?

What's the going price for a person's soul? We know what Robert Johnson's alleged price was. But what's the market like today? 

The guys at "Freakonomics" have again waded into provocative territory by asking just how far moral limits extend when it comes to markets. And to its extreme, the market for one's soul. 

Regular readers know I like "Freakonomics" and how Stephen Dubner and Steven Levitt often push us into uncomfortable territory. This recent episode titled "Soul Possession" may top the list, documenting one man's odd quest to own another's soul. He buys it -- at least on paper -- for $50, but a simple transaction is filled with all kinds of complex layers on both sides of the deal.

It's a fascinating topic, regardless of your faith.