Healthcare costs in Charlotte are the sixth-most expensive in the nation, according to a new list published by Forbes Magazine. The calculations are based on data comparing the average costs of preventive primary care visits as well as three standard procedures: CT scans of the head and brain, MRIs of the lower back, and lipid panels. Compiled by Castlight Health, a San Francisco-based company that works with employers to control healthcare costs, the numbers show vast differences in pricing both within cities and from one to the next.