The main thing that irks me, and I'm guessing many others, is that this code/feature wasn't in any of the feature matrixes at time of release.
It was added after people had made the full purchase, based on what was advertised, but then released at a later date for $600
I have no problem with Madness on IMDn Prem, nor additional mb on Tron LE, as these were clearly advertised as being one of the perks for ordering an LE, completely different argument.
It's the way this is released months after the fact that is seen as underhand.
I don't even believe that it can be likened to DLC for computer games. These games are generally extremely high volume so adding an option to buy a different coloured skin, or upgrade weapons earlier, or even an additional level to play means that the developer can get away with only charging a couple of quid because of the high volumes likely to be sold.
Releasing a limited number of toppers with this code at such a high price makes it abhorrent.