Darling, that's priceless! As Hepburn's letters fetch £11,250 at an auction, here's our guide to why notes from the past are creating a buzz for collectors

Matthew Haley, head of books and manuscripts at auction house Bonhams, says that authentic letters by famous or noted people have appreciated in value in recent years. 


He cites the example of a letter by artist and poet William Blake, which sold for £35,000 in 2015, having previously made £15,000 in 1992. The Hepburn letters, which were auctioned by Bonhams, were particularly interesting because they documented the early part of her career.