As outlined above.
1. That's a sales-rep and a dealer being greedy.
2. A good detailer will do it for a lot less. (£300 if brand new and not driven to reduce prep time)
3. It protects paint a lot better and should be good for 2 years depending on brand.
4. I have the PPFilm on the front of both Mogs and it has worked very well. Some question over the running boards and foot scrub marks? I would do it again.
5. The AUdi dealer I bought from used a local specialist but did add a little value by delivering the car directly to them on a covered truck still in it's bubble covers to reduce the prep.
Heinz in the UK MB don't do a factory option and it is left to the dealers. Its all part of the modern world of "value add".
Car paint protection, tyre insurance, payment protection (we know where that went last time) after market insurance warranty extensions. It goes on forever.