Thus highlighting the difference between monetary value and what is actually useful. It's a difference people get confused about too often - thinking that the most important thing on the planet is the economy; thinking that everything is fungible because it has dollar value. It's all fun and games until we hit resource limits of the planet. Or kill someone. Our economy sucks at pricing in the fact that while we can safely run out of tullips, we can't safely run out of clean air.