"Last year, we were having to explain who Banksy was and why his canvases were 30,000 or 40,000 pounds ($60,000 to $80,000)," Andipa said. "This year, every single person - including clients who'd come in their Lear jets - walked in and said, 'Wow, Banksy - and it's only 150,000 pounds ($300,000).' "
Such prices are no longer exceptional. Last year, a Banksy went for almost $600,000 at a London auction. Earlier this month, "Keep It Spotless" - a Banksy stencil over a polka-dot painting by British artist Damien Hirst - sold for $1.8 million in New York.
The 60 works in the Andipa show range from $15,000 for limited-edition prints to $900,000 for a painting of sharks circling supermarket trolleys full of bright orange fish.
Banksy's opinion of all this can only be guessed. Andipa does not know or represent him. The works in the show - on wood, canvas, fragments of wall, and pieces of metal - were bought from collectors around the world.
Banksy's website says the artist does not endorse gallery shows of his work and disapproves of auction houses selling his street art because "it's undemocratic, it glorifies greed, and I never see any of the money."
His publicist, Jo Brooks, said the artist had no connection with the Andipa show.
"It's absolutely nothing to do with him, and there is no comment," she said.
It's a classic Banksy contradiction that he is famously publicity shy, but also employs a publicist. He's an expert at blending an outsider image with commercial savvy. He almost never gives interviews, avoids being photographed, and has not even confirmed his real name.
Most agree his name is Robert - or possibly Robin - Banks, he is in his early 30s, and he comes from Bristol in southwest England, where he began his graffiti career in the 1980s and 1990s.
Using spray paint and cardboard stencils to tag walls, bridges, and street signs, Banksy evolved a cheekily subversive style. His most famous images include two police officers kissing, armed riot police with yellow smiley faces, and a chimpanzee with a sign bearing the words, "Laugh now, but one day I'll be in charge."
