What's a fair price for one life?

Given the rash of natural disasters in the last few years, and the generous outpouring of donations to victims in New Orleans, Indonesia, Burma and China, its remarkable to see economists attempt to parce the value of one life.

One method, say the authors of Freakonomics, is to look at the amount of money donated to support those causes, and how it has diminished per capita over time. See the NYTimes article here:

http://freakonomics.blogs.nytimes.com/2008/05/13/how-pure-is-your-altruism/

There's also another, more direct "price point" set for one human life as a result of insurance claims for those disasters and others like the Lockerbee airplane bombing settlement.

I'll look for more info on those to seed this economic / valuation of life, and to question if it's fair or not.