The diesel engine needs more frequent oil changes and more frequent fuel filter changes and diesel in many areas costs as much as premium gas at the pumps. With the 8 cyclinder diesels the cost to rebuild the injectors is around $5,000 and it can happen within 100,000 miles of driving.
Buy a diesel for more torque to pull a heavy trailer and for the exhaust brake to control speed on steep downgrades but do not buy a diesel to save money. I currently own a diesel 2500 and was towing a 13,000 lb boat load but having sold the boat I will be selling the truck and replacing it with a 1500 class pickup with a gas V-6 engine.