Biodiesel Lawn Mowers for Sale

The guy in the picture is JP Patten, entrepreneur and computer expert, shown with his newly outfitted biodiesel lawn mowers. Now, I think this guy’s got a great idea, he buys lawnmower motors from China, takes them apart, rebuilds them so they burn waste grease from deep fryers.
So far, so good. He says the engines are more powerful and more efficient than their gas counterparts, and they cause much less pollution. Ok, I’m sold, but how much are they?

