I think people need to remember games like COD and GTA are the few games people actually think are worth 60 bucks these days.
A lot of the smaller games are sold for under 60 bucks after a few weeks and are then mostly tried by gamers in the used game market.
I can't recall the last time I paid 60+ bucks for a game apart from GTA and COD.
Thing is people know that GTA 5 is a game that is worth the 60 bucks as it will provide tons and tons of gameplay.
While smaller games are different but do not have that massive epic scope to justify the same price.
Point is if you have everything at the same price, the stuff that seems more "fun" or epic will get chosen.
Sure AC is the same gameplay but each game has a whole new world attached to it and it has a pretty interesting story.
COD is the same thing I agree, but the game offers a lot... a 5-hour Campaign which is a bit over the top but quite better then the likes of other Shooter games, Zombie or Extras Mode and a very popular Multiplayer.
So people need to realize Indie games that are different can't simply compete against these games selling at the same price.