DAVID GREENE, HOST:

Good morning. I'm David Greene. Last year, British graffiti artist Banksy took New York by storm with a month-long guerrilla art campaign. Part of that included putting dozens of his signed, spray-painted works up for sale for just $60 each at an anonymous sidewalk stall. It was not a huge success. Over seven hours, just three people bought eight pieces of art. Now two of those have been sold at auction in London for $215,000, roughly 1,800 times the original price. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.