Would you pay the extra three grand to get a hundred miles per gallon?
Sure. Why not? A few years ago when I was considering a new truck, I considered the extra three grand for a turbo diesel instead of a gas engine ... based on the price difference between unleaded and diesel, and the difference in fuel mileage, I calculated that I would come out ahead after something like 125,000 or 150,000 miles. I drove my last truck to almost 275,000 miles, so it was a no-brainer.