Nice video and great review. I own a K3 for 7 years and a K1 for 3 years. Both great camera's. I bought a K3-III and yes, it is expensive, but I have been using it now for a couple of months and I'm very happy with this camera,especially the autofocus.
I live in a small town and we have an International moto-cross track and when there are no races, the track is used for training purposes and as a photographer, you can go-in for free and take some pictures from the pilots training for there next race. You have a lot of pilots from all over Europe that come to this place since this track has a very good reputation.
Now with the K3, I get max 4 shots out of 10 that are in focus, the K1 is a little bit better but no more than 6, but the K3-III, it is a just amazing how fast the autofocus works. In some cases I get 10 out of 10 in focus.
So is it worth the 2K euro, for me yes, is 2K a lot, yes, but some people buy a mobile phone and pay more than 1K and they have to replace after 2 or 3 years.
Check for yourself, see link for the pictures, all shots taken with the 70-200 lens in jpg. no photoshop used, just straight out of the camera.
K3-III - Google Photos