:/ Well it is their product
You do realize Activision are only doing this (or, were only doing this) because apparently they've been "hit with the recession" or something akin too that. Now, Activision are quite a big company, and they've produced a fair few popular games, and yet none of the other games companies are up-ing the price, even the ones who are smaller than Activision.
Basically this is just Activision wanting more money, or at least, originally it was.
Oh, and I can understand Collectors and Special editions being priced higher... but... still.