Congratulations on the new adventure and welcome to the forum!
We just came back from a trip to Grand Isle Louisiana and Voice of the Wetlands Festival in Houma!
We were very surprised at the cost of diesel fuel. Generally in the $3.34 to $3.65 range. Gas was pretty cheap, in the $2.35 - $2.65 range. Mississippi has excellent gas prices with Arkansas and Louisiana being about 5% - 10% higher. Missouri was on par with Mississippi.
I must say, our Chateau 23-U w/ Ford V-10 is very easy to maintain and service. I do oil changes and most things I do for our cars. It gets 8-9 mpg and has plenty of torque to pull. It's bigger than a Sprinter, but not so large that we can't take it most places. With our scooter on back, we have the best of both worlds!
Good luck with you choice and enjoy the ride!