Cost of Bariatric Surgery. The cost of bariatric weight loss surgery is typically about $25,000. In general gastric bypass surgery procedures are more expensive, costing in the range of $18,000 to $35,000, while gastric banding procedures run from $17,000 to $30,000.The cost of surgery includes the following fees:1  Hospital fees.ost of Bariatric Surgery. The cost of bariatric weight loss surgery is typically about $25,000. In general gastric bypass surgery procedures are more expensive, costing in the range of $18,000 to $35,000, while gastric banding procedures run from $17,000 to $30,000. The cost of surgery includes the following fees: