A Paris auction will feature some of the world's most valuable comics

The value of an item, the adage goes, is never less than what someone is willing to pay for it.

And for rare comic books, that value is skyrocketing.

At a sale at French auction house Artcurial on April 30, comics - especially those written by the famous Belgian cartoonist Hergé - will receive attention and prices rivaling those usually reserved for fine art.

"The world of comic strips has recently witnessed a renewed enthusiasm," said Eric Leroy, an expert in comics at Artcurial.

"Collectors come from all backgrounds; some of them have previously been collecting contemporary and modern art and appreciate the graphical and historical side of collecting comic strips," Leroy said.

Artcurial set up a dedicated comic strip division in 2005, responding to a rapidly expanding market and a growing need for in-house expertise to identify, authenticate, and curate some of the most desirable comics in the world.

"Quality works are getting harder and harder to find, but some aspects of comics are always important: the rarity, the album it originates from, whether the hero is depicted, the talent of the artist and the condition of the work," Leroy said.

The auction this month will include items from the personal collection of French pop singer Renaud. It heavily features the work of Hergé, creator of "The Adventures of Tintin," a series of graphic novels depicting the worldwide escapades of a young Belgian reporter.

The series has to date sold well over 200 million copies in more than 70 languages, and remains in wide circulation.