I assume you're talking a 1 ton diesel crewcab 4x4 at the prices you're talking.
If you're someone that trades often, lease. If you buy a diesel for the long run, that's where the value of a diesel lies.
My 117K mile F250 is almost 12 years old, and it still looks and runs like new. My Lariat crew cab 7.3 diesel with all options except 4x4 cost $32K new, and it's still worth quite a bit.
We're sorry to see that Canadians have to pay so much for your vehicles, taxes, etc. It's simply an expensive place to live. We hope to see you in Florida for the long winter, however.