How much should gas cost?

My recent six-part series on Clean Energy Conversion (I hope you’ll read it …) began with the bold assertion
Dirty energy is cheap and that’s a problem.
An important CBS News editorial estimates the actual cost of gasoline … $11 to $15 per gallon. Why doesn’t gas cost that much at the pump? Because we subsidize it with our taxes, with the lives of young soldiers, and with our health and ecological well-being. I hope you’ll take a few minutes to understand our need for a clean energy conversion – both from CBS News, and my series:
Part 1
Part 2
Part 3
Part 4
Part 5
Part 6