Art, for the most part, has value because it is expensive and is expensive because it is valuable.
People want to spend money on it. From millions of dollars for a super high end piece to a couple hundred for a minor "name" artist's piece, there are markets for every price point.
The trouble with art is that there's so much of it. It's being made by millions of people, constantly. And, it's not all bad. And what IS good or bad, anyways? The result is that you wind up with artificially created markets defined by designated tastemakers. So and so decrees that that guy's sculpture of welded together car parts is worth $1.5M. This magazine decrees that this other guy's photos are worth $750. Once the price is set, the artist's name is dumped into a price-point bucket, and people buy the work based on the fact that the artist has sold other work at or around that price point.
It's not *completely* arbitrary, mostly the expensive stuff has some merit of some sort. It might not be to my taste or yours, but someone probably genuinely thinks it's good work. Still, there's lots of good work out there, and not all of it is salable at all.
How do you get to be a tastemaker, one of the gatekeepers of the community? Well, that's complicated.
How do you get the ATTENTION of a tastemaker? You sleep with them, you hang around with them, you're related to them, or you're just plain lucky.
So yeah, in a sense it's all in the name. Some names are picked out of the hat to be lucky winners, and most names are not.