Perhaps this will help.
PPF would be worth the money if you get a lot of small rock chips etc that is not strong enough to puncture the film, which is shown well in the video.
However, in the case of bigger dings and scratches that would penetrate the film, PPF seems like a waste of money.
On top of that, proper installation with special care to the edges of the film is very important because poor installations often cause other problems like dirt and grime starting to accumulate in the edges of the film or the edges starting to peel, etc. after a few years. So I would not recommend searching for the cheapest installer for PPF.
Personally I spent 7k to apply PPF to all painted surfaces of the car and headlights. I know value-wise, it may not be a great choice. But I do get a sense of peace of mind knowing that the car's paint will not be affected by most rocks or debris that come my way. I may still get a few big enough dings that go through the film over the years, but without the film it would be much more frequently.