Twenty years ago, a 1950s three-volume Lord of Rings set would sell for between GBP800 (NZ$2,200) and GBP1,000 ($2,700). Now it would sell for between GBP17,000 ($46,000) and GBP25,000 ($68,000).

According to the BBC, a set of Harry Potter first editions can sell for at least GBP25,000, too. "The recent success of the Harry Potter and Lord of the Rings films have boosted the prices of the books on which they were based, making bibliophiles everywhere wonder if they have a rarity among their collection."

The article quotes book dealer and Antiques Roadshow expert Clive Farahar (pictured). A search through the Farahardupre catalogue throws up some interesting New Zealand-related items: not least a tinted lithograph of Nelson going for GBP225 ($615), and a pirated French edition of Cook's First Voyage, offered for GBP1,500 ($4,100).

After you've checked your shelves for J K Rowling and J R R Tolkien, the BBC has some useful advice to offer: buy books you are interested in, buy in as good condition as possible, preserve modern first editions by not reading them, and remember that "rare does not necessarily mean desirable".