Not quite 2yr since my post above but worthwhile updating because I too have now fallen victim from this failure. It did happen in a crematorium car park so can't fully rule out that poltergeist theory however my passenger took full responsibility for snapping the plastic strip.
So having now taken a more detailed interest in the subject, there is or maybe an additional cost, that nobody mentioned above. The plastic protector which is dirt cheap ( less than two gallons of fuel - why are people getting so upset? ) is connected to a wire mechanism which is then connected to - I'm guessing some mechanical input from the hinge. Now whilst that visible plastic protector may be dirt cheap, the cable mechanism is not. In fact for what it appears to be, it's ridiculously priced. So if the cable snaps or breaks in some way or just needs looked at, then it's certainly not a 5min job. First of all the door card has to be removed / replaced and the cable mechanism itself needs to be removed / replaced. Is that not a more plausable reason why people have been quoted three figures to have the protector replaced?
I'm not 100% sure if my cable is broken or not but having some basic knowlege of how things work, it's certainly something I'd want to look at and possibly try to repair myself. Even if a repair rather than replacement is possible, that's still justification for a dealer to charge for their services.
I was under the impression it'd just be a simple case of replacing the plastic protector and as per above, it'd be a 5min job. But I have to say my local dealer was more than helpful explaining how things work, giving me part nos etc. At this stage all I've ordered is the plastic strip as that'll defo need fixing, but all I have is praise for the dealership for their help. At the end of the day, they're not charities, they do have to run a business.