So I generally agree with all this. But in my opinion there's a limit to how much money you can justify with "it's art". If you're making 150 of something, you shouldn't be justifying a particularly huge price with it being art. If it really cost
that much, and the price of making just one would have been ridiculously huge, then there
is a point where I'd say the whole project is not worth it, is not making the world a better place. (Note: I am not stating any opinion on where this watch is relative to that level.)
Or to restate and elaborate on my original point: 99% of the time, it's fine to use art as a reason to buy something. You don't always have to be donating every dollar to charities. But for any level of justification you want to reach for the price of a piece of art, the dollar amount that fits under "justified" depends on how many copies are being made.