Jim,
I have the 2006, 5.9L Cummins. I change the oil every 5,000 miles. The same for the gas F250 I had. Cummins does swear that changing oil is every 15,000 and that the motor will go 300,000 miles as such. But I am old school. I stick with every 5,000. I think Jay does every 15,000. So, as far as oil changes, diesel is the same or less than gas.
Every 15,000 miles is a $11 fuel filter. Takes about 4 minutes. And that is it. There is very little maintenance on a diesel. Just oil and filter.
Fuel consumption, in my case, is about 50% better with diesel. The price of diesel fluctuates here in Ventura from the same as regular gas to the same as premium. Out in the less populated areas, diesel can be less than regular. I do buy biodiesel when available. We now have it in Ventura again though only B20.
The initial outlay for a diesel is expensive but you get back every penny when you sell. When I got fed up with my Ford gas F250's lousy mileage and terrible suspension. I put it up for sale. Even though my ad stated "gas", it took me 2 months to sell it. Every call I received was "Are you sure it isn't diesel?" I took a bath on resale. Had it been a diesel it would have sold high and within a day.
So my take? Diesel in the long run saves you money.