Oil over $75? It may be worth the trouble? Probably needs to be constantly over $75 or more though?
The problem with any oil, is as most learned in junior high. Most of what is used is gone and is not replaced? So there will be constantly less and less of it as time goes on?
Maybe if dinasours came back? And a few million years later? ;(
Replaceable-reuseable stuff is what our future needs.
Of course most of us won't be around? But, the distant future will need us to start doing something soon?