Lee Rosenbaum's
Culture Grrl blog is good for general US art market news and arguments over stuff like de-accessioning, artist's legal rights and artist's sale royalties. I'm not sure just what her standing in the art world is, but the posts are always well-informed, and thoughtful. If you want to know more about the workings of the art market, as opposed to the art, this one's useful.
I give it a 6.5
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)