Man brazenly walks out of art gallery with $20,000 Dali painting under his arm

https://www.independent.co.uk/news/world/americas/salvador-dali-painting-stolen-theft-san-francisco-dennis-rae-fine-art-a9158126.html

The Dali piece “Surrealistic Bullfight: Burning Giraffe” was stolen from Dennis Rae Fine Art gallery in San Francisco. The piece mentioned that the thief cannot sell the piece on a site like eBay because it's such a unique piece, but it begs the question: what is the underground art market like? Who are the buyers?