We are soon to be RVers and are looking for a truck that will comfortably pull 9K. Probably will be going with a 5th wheel but havent ruled out a pull-behind. Basic parameters are 3-4 years old that has less than 40k miles.

We had pretty much decided that a 250 would do the job.

My wife and I went down to the local Ford dealer yesterday to look at a 250 they had advertised. Upon arriving at the car lot, our eye caught a beautiful '08, F350 dually, 2X, 6.4L TD in excellent condition 36k miles at a really good price (we've been shopping alot so we know a good price). I said what the heck lets just look... bad idea!! now we fell in love with the truck.


My question:
What is the downside of owning a 350 vs 250. i.e. gas mileage difference ... dealer says about the same. Any other advise would be much appreciated.