I notice that book has a list price of $16.99 but can be bought from the same site for as low as $3.99. Same situation with oil really. You can pay $120/barrel for oil or you can convert to natural gas at maybe $40/barrel or electricity at $20/barrel equivalent.
Soon you will find copies of that book at op shops and garage sales for 50c or less and perhaps it will become a viable fuel in its own right?
