For many years, vinyl versions of works by artists such as Bob Dylan and the Beatles have been highly prized by music fans, but now CDs are starting to become seriously collectable as well.
Despite only being around for several decades, the latest "bible" for those who collect records includes a new compact-disc section.
It lists the most valuable CD as being worth 3,000, although the name of the band is unlikely raise eyebrows.
Only 140 copies of a promotional CD called The Beatles at the Beeb were released during the 1980s by Apple and, according to the new edition of The Penguin Price Guide for Record & CD Collectors, there are only 17 vinyl records worth more.
The book’s author, Nick Hamlyn, claimed the trend was proof that the recorded-music market was evolving.
He said: "The inclusion of compact disc in the price guide’s title is highly significant.
"Although a few die-hard vinyl specialists will complain bitterly about the fact, the silver disc has now established a significant place within the collectors’ arena.
"A large number of collectable CD albums and singles are included in the listings, and while their values cannot compete in general with those of the most collectable vinyl items, the fact they are there at all is a demonstration of the way which the market for collectable recorded music is continuing to develop.
"Whatever the debate about how authentic the sound of CDs are, they are still an important part of musical history which is why after two decades they are now collectable. They were introduced to a somewhat sceptical public but they have gone from strength to strength since."
The sixth edition of the weighty book includes a list of the 23 most collectable CDs in existence - though it also includes thousands in its index, alongside their values.
The list includes two CDs now worth 750 each to collectors: a Nirvana promotional recording from 1994 called Penny Royal Tea and U2’s Rattle and Hum promotional set of LP, CD and cassette released in 1988.
Also on the list, worth 500 each, are a Japanese double CD set of Kate Bush and two private pressings of Elton John and the Rolling Stones, also from Japan.
Other artists to figure on the collectable list range from David Bowie to John Lennon, Michael Jackson to Queen, Oasis, Pet Shop Boys and Pearl Jam.
A single Elvis box set in either gold or silver, called Legend, and put out in 1983 is worth 250.
CDs still have some way to go to catch up with the most valuable records, particularly the top two, both versions of Freewheelin’, the album by Bob Dylan. One is a US stereo version released in 1963 with four different tracks and worth as much as 20,000.
The other is the mono version of the same album, worth only half as much at 10,000 even though it is the second rarest record on the market.
Also worth 10,000, according to Mr Hamlyn, is There is Love In You, a single by the Prisonaires from 1954 on Sun records, and Billy Ward & His Dominoes - the name of both the band and the 10in single, also from 1954.
Rare Beatles records feature prominently in the list, whether it is a sleeve that was only printed on some copies or a test pressing that was never widely distributed.
Compact discs were first launched in 1983. Although sales of the new musical format were initially sluggish, worldwide unit sales hit 600 million in 1989 compared with 450 million vinyl records.
Last year, a total of 50.9 million CDs were sold in the UK - a rise of 22.1 per cent compared with 1989.