Lightweight autos do not need to cost more. The U.S. MY 2010 new-car fleet shows little or no correlation between lighter weight and higher prices. There’s also a large vertical scatter in price in each of three broad price bands, and conversely, a huge weight range at the same price.
America Online. 2011. "New and Used Car Listings, Car Reviews and Research Guides - AOL Autos." America Online. link