The plastic cases, the labels, and the thin leaflets cost only a few cents. Many of the "special" features actually come from free sources, such as press releases, interviews, trailers, and so forth. And the more important question isn't whether a DVD will last but whether companies will still support the format in the future.
If we follow the arguments given by the former general manager of Hyperion, only around 35 percent of the price of a DVD goes to the DVD itself and royalties. The remaining 65 percent goes to the wholesaler and the retailer, and except for shipping and storage, a significant portion of the costs goes to marketing. It is, in fact, this marketing that creates the illusion of quality and fun. It is also the same marketing system that allows producers to release and re-release the same stuff with incremental "special" features or "new" editions. And it's not accidental that the same producers make mostly films that sell only because of their entertainment value. (This shows that censorship in other forms do take place.)
In many ways, most DVDs that are currently marketed are sold in the same way as audio CDs for almost twenty years: overpriced and hyped. What's strange is that the same companies also invest in disk recorders and blank disks, which is why they end up profiting from one industry while changing the format of another.
It is possible that once cheaper, faster, and error-free DVD-RW drives appear, then companies will come up with another format while making money from DVD recorders and blank disks.