These little cardboard, Banksy replica postcards were one of the few reasonably priced Banksy authenticated items. They were available for a few months a few years ago from the British museum. Banksy famously snuck a similar piece on stone into the British Museum and it wasn’t discovered for a few days. He actually snuck paintings and other art into seven major museums, including the MET in New York in the Louvre in Paris. For some of these pieces, it took days to discover that they were placed there. Absolutely brilliant! These little pieces are still highly collectible. They’ve gone up in price over the years.