It is hard to think of a more remarkable bargain than “Misty”, the diplodocus that went under the hammer this week for £400,000. The chance to own a 17-metre dinosaur does not come along every day, after all. So remote from us is the Jurassic period that the odds of even the tiniest fragment of a diplodocus being preserved, let alone discovered, is staggeringly small. The specimen auctioned at Billingshurst on Wednesday was one of only six in the world. Whoever bought it got it for a snip.