As automakers race to make cheaper electric cars with greater battery range, General Motors is working on one that can go 200 miles per charge at a cost of about $30,000, a top company executive said. Vice President of Global Product Development Doug Parks wouldn’t say when or if such a car will be built, however. … The 200-mile car would cost about the same as the current Volt, and it would match the range and be far cheaper than Tesla Motors’ $71,000, all-electric Model S. The Model S can go up to 265 miles on a single charge. …