When I rent movies, do I devour the DVD extras? Sure, lots of times the audio commentary is just a track of actors and directors waxing important and mostly ignoring the images on the screen, but they can still be dishy and insidery, and for my favorite movies, they can almost make purchasing the DVD worth the money.

Disney DVD knows there are lots of fans like me. For years, it has released its biggest titles in a variety of volumes. There's often a simple one-disc version for people who just want to see the movie without any extras, and maybe a two-disc version loaded up with more outtakes and mini-documentaries.

Maybe there was a version for people who own the Blu-ray system, which offers high-definition. If they wanted to see all the bells and whistles, customers could get the most elaborate version for whichever home system they owned.

Not anymore. Disney has begun placing its best and most complete supplementary material on just one edition: the niche Blu-ray one. If you, like most Americans, have a standard TV and you want to buy the most elaborate version of Pixar's animated "Up" that works on your TV, you won't get all the goodies.

Only people who have shelled out to pay for expensive Blu-ray equipment will have access to all the documentaries and extra materials that, until recently, any fan could own. That means that on top of a Blu-ray player, you'll need an HD TV and new cables.

Unsurprisingly, the Blu-ray disc itself is also the most expensive, with a suggested retail price of $45.99 versus $39.99 for the most complete standard version available. The low-frills, one-disc release has a suggested price of $29.99. Renters make more money, too. Netflix charges more to rent Blu-ray than it does to rent standard DVDs.

Although prices have been falling for the discs themselves, sometimes that's only as a means of driving customers toward the new format.

With more standard DVDs available for $5 to $10, it won't surprise you to learn the major Hollywood studios are unified in pushing us toward this new, more lucrative format.

A spokesman for Walt Disney Studios Home Entertainment told WalletPop that the forced upselling tactic goes back at least as far as the release of Pixar's "Ratatouille" two years ago and has been the case for several of the company's old-school animated re-releases, including "Snow White and the Seven Dwarfs" and "Pinocchio."

Blu-ray holds more space than standard DVDs, and it can support interactive menu formats that standard DVDs can't, but it's still possible to furnish almost all of the same documentaries, alternate scenes, and other behind-the-scenes materials to customers using standard discs. Disney just won't, and along with some other entertainment manufacturers, is nudging everyone toward the more expensive option by simple cutting off the least expensive ones.

Forcing customers to higher-priced models is nothing new. Canon has been actively doing it in its cameras. A few years ago, it offered pocket-size digital cameras that had swing-out, "vari-angle" screens to make it easier to line up shots. Now, those swing-out screens are only available on bulkier, more expensive models, which forces customers to spend a lot more to get the same features.

When I asked Canon to comment on the reason behind that change, it extended a vague rationale, saying "industry demand and consumer trends have changed through the years. Today, we see a shift in consumer needs for a smaller and slimmer form factor."

Still, Canon did better than Disney did in at least acknowledging its change. Disney didn't even get back to me to explain why this kind of exclusionary packaging is better for customers.