£12m for a Pokémon card? If you’re not in the game you’re missing a trick

The record sum paid at auction for a rare example is part of a boom in trading cards – and the prices can be staggeringFor £12m, you could buy a seven-bedroom mansion in Hampstead, north London, or a Bugatti La Voiture Noire, one of the world’s most coveted sports cars, with a fe...