A very rare experimental 25 pence British coin from 1981 that looks at first glance like an ordinary 20 pence example has sold at auction for some 6,800 times its face value. Estimated at £500 to £700 ...

Millions of coins and bills pass through our hands every day, most of them worth exactly what's printed on them. But some coins can be worth a whole lot more, thanks to their rarity, condition, and ...