Oh no. Thats really bad luck. Will your Insurance cover it ? Double that damage and my Insurers ( NFU) wrote the vehicle off as beyond economic repair....having fixed it I now tend to agree !
If you go for new then, based on my rebuild, doors are well over ?300, wing about ?120 just for the panel. The problem is that decent old doors are hens teeth to find. How bad is the bulkhead ? I was lucky, the bulkhead could be pulled out and filled, it had just been creased by the mirror arm folding in on it.
If replacing the old door with the more modern "rounded corners" type you will need a new inner panel to hang the window regulator off. Everything else swaps over, even the door-trim, apart from a triangle about 2 in long that needs shaved off to fit.
Its all bolt on-off but replacing the bulkhead will be a big job, so much stuff attached or running through it :-(
I have a scruffy passenger door you can have if its any use.