|The Fury said:
Depends on the case, person or game. I mean Dragon Age Inquisition, currently on PSN for £30. GOTY Edition is £55. Go into a highstreet and internet store and get the GOYT Edition for £25 or less at the moment, which is the price of the included DLC alone on PSN without the full game as well. Inquisition isn't even available on Steam because EA. This would have hurt their PC sales, they seem to not care however.
Funny that you mention the GOTY Edition of Dragon Age Inquisition. Once you typed in the redeem codes of the DLC (and it gets bound to your account), you already destroyed most of the resell value of that game. ;)
You also have to download the DLCs, they are not on the disc: http://www.eurogamer.net/articles/2015-09-25-dragon-age-inquisition-getting-game-of-the-year-edition
So after the shutdown of PSN / XBL or Steam you won't be able to redownload these DLCs even with your physical version of the game.
If you sell the game, you can't play the DLCs anymore (because you don't have the main game) and the buyer can't use the DLC content either.