Perhaps the smartest article I've read regarding this particular mystery. (The major mystery being that at over ten grand for the cheapest one in gold, Apple is for the first time making "Veblen" products, meaning products which get their main value from perceptions, status, and a very high price.)
The gold watch will never make much money compared to the iPhone, but it will change Apple's brand forever (it's already the only tech company which could pull off something like this), and it will change the sales of the cheaper watches, perhaps a lot.
I hope Apple has been smart enough to make the insides upgradable, that will create a lot of happiness and goodwill from gold-watch-owners in the future.