Fully loaded diesel is over 65k I’m pretty sure. So yea it’s not gonna be cheapTechnically in CA we already could given it was in the Durango which is classified as a suv. It would need to retain all the emissions equipment from the donor and pass smog/inspection by a ref. Typically, people will buy a whole vehicle like @Indy did when he swapped in a 5.3 from a tahoe. I believe it is harder if you were just to just by a crate engine.
If its less then 65k I'd be shocked. Unless down the line you can get one that isn't fully loaded.