When is a DVD worth $400? To DVD enthusiasts, it's when said disc is a rare Criterion white-ring issue of Pier Pasolini's 1975 film "Salo," which can go for upwards of a few Benjamin Franklins in today's collectors' market.

You see, Criterion -- that bastion of cinematic preservation bringing classic films, foreign titles, and director's cuts to North American armchair cinephiles -- has released over 300 titles in its 23-year reign as every movie fiend's best friend. That oeuvre is composed nearly entirely of critical classics ("The Rock" and "Armageddon" notwithstanding) that usually sell for between $30 and $40 -- until, that is, distribution rights to a film expire. Once a disc goes OOP (Out Of Print), its Criterion value shoots skyward.

Currently at least 18 Criterion titles have gone out of print; if one is so lucky as to own the Criterion issues of , say, "RoboCop," "This Is Spinal Tap," "Rebecca," or John Woo's "The Killer," that DVD can be worth over $100 alone. (And if anyone has a Criterion copy of Perry Henzell's "The Harder They Come," our own Tim Ryan may fork over a fortnight's pay to get his hands on it.)

That isn't to say these titles aren't available in standard issues -- you can find a non-Criterion (read: barebones) version of Pasolini's "Salo" on EBay for the cost of $5.95. But as many cinema lovers know, when Criterion issues a DVD, it gives a film the royal treatment: movies presented in their original aspect ratios, in discs packed with in-depth special features and bonus materials.

Adding covetousness to the allure of OOP discs is the designation of the "white ring." Signifying a particular film's limited Criterion release, a Criterion DVD bearing a frosted white center can boost a rare issue's value into the realm of extreme cost. The white ring means hard-to-find. The white ring means expensive (that is, if you can find it for sale and verify its legitimacy). The mere mention of the white ring is enough to make any true DVD collector drool with desire, like a Pavlovian dog with a home video fetish.

Thus is born the $400 DVD. Arguably the most expensive disc these days is the Criterion issue of "Salo" (also known as "Salo, or the 120 Days of Sodom"), Pasolini's 1975 film adapted from the Marquis de Sade's satirical story of wealthy libertines holed up in a castle to defile and debauch a group of adolescent children. Pasolini transferred the story to a 1944 Fascist setting, but the graphic nature of the film's numerous rape, sex and torture scenes led to widespread banning in multiple countries.

Released by Criterion in 1998, the DVD was only available a short time before licensing conflicts intervened and the edition was pulled. The desirable Criterion white ring edition of "Salo" is rumored to go for as much as $500 at times; one current EBay listing offers it for the Buy It Now price of $399.95.

However, the folks over at Criterion have announced that they've regained the rights and intend to re-release "Salo" sometime in 2007 (and in HD!), so you'd better hurry up and unload that cache of white ring "Salo" DVDs fast. (Incidentally, Criterion's On Five blog is a great read for a behind-the-scenes look at the company's goings-on, including their process for choosing cover art for Jules Dassin's "Night And The City" and "Thieves' Highway.")

Oh, and if anyone's in the market for the entire Criterion Collection to date -- 320 titles in all -- get ready to fork over a cool $7,000 for the lot of 'em. (Hey, at least shipping is free!)

[Thanks to our great Forum members for bringing such interesting topics to mind!]