Yes, and its because of christmas. I was very lucky to pay for this item at less then $30 because every were else the game is $40 or more, even on ebay.com and I alway thought ebay would be cheaper then Amazon.com but i was rong. Thanks to Amazon I saved a lot of money Thank Amazon.com :)
I bought it at a Target store for $20 the other day. I looked online today and I saw that everyone else was selling it for $35-$40, which lead me to think that maybe I found a mispriced copy at the store. Well, go to the Target website and, sure enough, it confirms the $20 price:
The catch is that it's only available in stores, not online. If you have a Target store nearby, and you want the game, I suggest you get down there and scour the shelves for a copy. I got lucky and found one sitting on the front of the shelf, and I wasn't even looking for this particular game. Heck, I never even knew that Rockstar made a "complete" edition with all of the DLC content and the original game bundled together until I saw it on the shelf!
This was such a great deal that I bought the game even though I don't (yet) own a PS3. I just ordered a PS3 tonight from NewEgg.com (the 320GB Uncharted 3 bundle for $300).
Interestingly, the Target website lists the regular edition of GTA4 at $4.50 more than the complete edition.