Now that Mercedes has announced pricing for the USA release of the B-Class ED, we know that the optional range package, which includes the ability to extend electric driving range by 17 miles, will cost $600.
http://www.myelectriccarforums.com/...ss-electric-drive-add-17-miles-range-for-600/
http://www.myelectriccarforums.com/...ss-electric-drive-add-17-miles-range-for-600/