DLC and Tiered Gaming: A Scourge of Modern Gaming?

Mana Pool is offering up a new editorial that examines the criteria the author feels is important when determining a video game's value, and how DLC, CE-specific content, pre-order bonuses, and other promotions have impacted such a value in recent years. Baldur's Gate II, Mass Effect 2, The Elder Scrolls IV: Oblivion, Diablo, and Dragon Age: Origins are all referenced:
Specific kinds of DLC are only available under certain conditions, and Mass Effect 2 is a good example of this, yet again. There were a few in-game items for Mass Effect 2 that can only be obtained by finding codes from cans of a particular soft drink, and only during the run of the promotion. Not even money is enough to play the full game! Made even worse is the fact that one of these items is arguably the best of its type in the entire game.

Worse still, as I recently discovered, the experience you can have in a game now depends on where you buy it from, as is the case with Mortal Kombat II.

Another example of this is special/premium/pre-order editions with additional content. I, for one, don't mind the specific shiny nature of special editions which come with real-life thingymebobs such as maps, 'ËśMaking Of' documentaries and prettier covers, but having one-time-only editions of games which come with additional content grates quite a lot. If I buy a game later (especially much later, in many years time), should I have any less of a fun/complete experience simply due to time elapsing?

It's worth noting that this last one isn't anything new, though even Baldur's Gate 2: Shadows of Amn suffered from this, with two special merchants that could only be obtained by pre-ordering. Thankfully, the protections on this weren't very strong, and the files for this were proliferated throughout the internet, but neither this nor the knowledge that it is not a new practice makes it any less of an irritating practice.
It also makes it very difficult when we're creating subsites and doing equipment databases and such, since we have to try and track down every incentive so that we have access to it.

This also brings back memories of getting Interplay and BioWare's permission to make the CE merchants available for download on GameBanshee so many years ago. I believe we were the first site to provide them, at least legally.