There is also the distinction between Jewelry and Horology high end I guess. Cartier and Van Cleef to use the present examples are well known and respected jewelry more than horology brands. I say this fully acknowledging the historic place of Cartier Watches which I happen to really like, having several of them between my wife and me. But I don't fool myself into setting Cartier against Patek, Vaucheron, JLC etc. I admit I don't know much about Van Cleef but even looking at their website I wouldn't think they are particularly focused on watches. (I may be wrong)
Just because something commands a price that is beyond the reach of most people, or because it is exclusive, (for example a one of 10 piece) that doesn't mean it is high end to me. Anyone can make a limited edition and anyone can price it on the stratosphere....but high end CRAFTSMANSHIP is more what I focus on. If it is exclusive and expensive because it is masterfully crafted, designed and finished then it is high end (even if it is a lesser known brand) If it is just Gold and diamonds and bling and basically a swatch dipped in platinum then it is just an expensive mid or lower end. Maybe priced well for it's value, maybe not, but not high end.