I’d say 6-8 hours for a professional. That’s assuming they have to start from scratch. They may have templates from similar cars that can be modified and save some time. It also depends on the level of detail you want. At a minimum you want a CLD inside the door shell and you want to seal the holes. Keep the OEM plastic and polyester liners.
If you can afford it, I’d also apply CLD on the outside of the door shell and CCF inside the door panel. Finish it off with a layer of MLV and you should be able to reduce the overall noise level by 8-10 dB. You’ll also have a big improvement in the quality of your sound system.
I don’t have a clue about the cost. My best guess is $600-$750.