My favourite example is that authentic Zimbabwe $100 trillion notes go for >$100 these days on eBay. And I say "authentic," because there's enough of a market t

My favourite example is that authentic Zimbabwe $100 trillion notes go for >$100 these days on eBay. And I say "authentic," because there's enough of a market that there are forgeries in circulation. (Reproductions are much cheaper, $5-$10.)