According to The Digital Bits, the new, cheaper X-Files DVDs are further proof to be careful what you wish for.

It turns out that you pay less but you also get less as far as the content is concerned. Seasons One through Season Three are currently on shelves for the low price of $49.98 per season set. The only problem with this is that a bonus disc is not included with these new sets. This extra disc contained such material as television spots and behind the scenes featurettes. This disc had been available with the previous more expensive incarnations of these season sets.

Also, if there happened to be any episodes of the show on these extras discs, those have been added to the end of the other discs to further slim the sets down.