When is £10 not worth £10? When yours starts with the serial number AA01, and might be worth up to £5,000. Perhaps printing them all with this serial number would address the fall in sterling? The new batch of polymer notes will enter circulation tomorrow, significantly slowing down the speed of transactions, as people check their cash twice to avoid exchanging a fortune for two pints. However, as we in the UK achieve the startling progress of upgrading from paper to plasticky paper; thrifty North Korean innovator Kim Jong Un is now allegedly ‘mining’ bitcoins to fund his regime. Worth virtually nothing five years ago a Bitcoin now trades at almost £3,000, drawing comparisons by JPMorgan Chase CEO Jamie Dimon to the ‘tulip mania’ of the 1600s. Otherwise put by US essayist Ralph Waldo Emerson: ‘Money often costs too much’, or by baseball legend Yogi Berra: ‘A nickel ain’t worth a dime anymore’.