Should I buy new or used diesel?

So I made a mistake by buying a new Ford focus st and now I want to get rid of it for a truck, I'm taking a big loss but I've accepted it.

I want to get a diesel and a boat.

I have found 2 options I like:
2006 2500 cummins with 98k miles in good shape for 28k

OR

2016 Ram 2500 Cummins for 43k new

The 06 is cheaper but 10 years old. Would it be worth it in the long run to just get the new?

In diesel pick-up years, ten years old is still wet behind the ears. Get to one with the nicer interior…

You just took your SAT and you think you can afford both a diesel and a boat?

You should probably keep the focus. But, it doesn't float well so stay out of the water.