The regular edition has a retail price of $59.99, which doesn't come as a surprise after Gears of War became the first Microsoft Game Studios game to sell for 60 bucks. The next one is Collector's Edition, for which EBGames has no info yet on the material included but it does has a price: $69.99.
Finally, the Halo 3 Legendary Edition, which comes packed into a Halo Spartan Mjolnir Mark VI Helmet replica will sell for $99.99.
In the case of the Legendary Edition, the retailer has some info on the goodies included:
Behind-the-scenes at Bungie Studios with new insights into the Halo Universe and the making of Halo 3.
A special hi-res collection of all cinematics from Halo 1 and Halo 2 with director commentary from the Bungie Team bonus.
Community content from Red vs. Blue, This Spartan Life and Exclusive Gamer Tiles & a Theme.
Each unit will be serialized for added individuality and collectability
It is worth clarifying that all editions have the same release date: November 1, 2007.