Part of the art market's appeal is it's opacity, though - there's plenty of manipulation that would be outright illegal in regulated markets, and plenty of dirt

Part of the art market's appeal is it's opacity, though - there's plenty of manipulation that would be outright illegal in regulated markets, and plenty of dirty money being washed through it - all contributing to the exploding valuations for fine art in recent decades. I wonder how much transparency and efficiency the art world actually wants, and what is the optimal amount to maximize art valuations.