It seems the contents of the Battlefield 4 Collector’s Edition have been leaked on a Russian website, and as of yet, is not available on the Battlefield 4 website.
Besides the game, the best thing in the set is definitely the Battlefield 4 beanie, and would definitely be something I would use, at least use from time to time. As for the rest of the Collector’s Edition, it also includes what looks to be a bracelet, hand grenade coffee cup and BF4 suitcase, as well as some other goodies.
As for the price, we are unsure as of yet, but it will probably be quite expensive, considering the amount of in game and real life items you’re getting. Here is the screenshot: