Someone else did some fair math (simple but fair) but you must assume that this game is not exactly sellout material as it was back in the end of Vanilla beginning of BC, so they would be manufacturing boxes with the added expense of the authenticator, that potentially wont ever be used. This will only translate into a more expensive purchase for the customer (granted it would be like 2 or 3 bucks, but having been paying for 2 accounts since the game came out I feel justified in saying even a few dollars more is too much.
Also, it is fallacy to suggest that an authenticator is a magic wand. In many cases people have their accounts stolen by doing the same foolish stuff online.
And I dont use "foolish" in a condescending manner, I've seen friends I consider at least computer savvy fall prey as easily as the biggest scrub.