I think it would take an eternity(in car years) for the extra $500 option to pay for itself. Being that it is a belt drive starter/generator will add to the maintenance costs.
He was talking about a 84 hp turbo charged model 451 passion. Going on to the http://smartmaniacs.co.uk/forum/, there are a few other instances of the newer models getting lousy gas mileage, but there are also several that get prety decent gas mileage. Several said that they didn't start getting very good gas mileage until about 5000 miles down the road. Others mentioned changing out the air filters and sparkplugs to increase the horsepower and fuel economy.I saw some pretty inaccurate mileage numbers somewhere on here posted by a fellow from the UK. He compared the Smarts mileage as being slightly worse than a CNG Mustang of all things!! I didn't bother to post as the banter did not seem to even warrant attention. And he quoted the mileage of an '84 Passion (no Passions in '84 that I know of in terms of cars anyway.... ).