Consumers shopping for health coverage in new online marketplaces may scratch their heads when they come to a handful of plans in Virginia: Why do some cost more than $1,800 a month? No, the plans do not include gold-plated hospital beds or guaranteed same-day access to doctors. Instead, those premiums reflect an add-on benefit for a type of costly surgery for obesity which makes them up to six times more expensive than plans without such coverage. That means a Virginia consumer considering gastric bypass or bariatric surgery will have to pay up to $1,500 a month more for plans that cover the procedure.