http://us.blizzard.com/en-us/company/press/pressreleases.html?id=4606414Diablo III will be available for Windows® XP/Windows Vista®/Windows® 7 and Macintosh® at a suggested price of $59.99 USD for both the retail DVD-ROM version and the digital version sold directly from Blizzard.
A special alabaster-white Collector’s Edition, sold exclusively in retail stores at a suggested retail price of $99.99 USD, will include the full game on DVD-ROM, a behind-the-scenes Blu-ray/DVD two-disc set, the Diablo III soundtrack CD, a 208-page Art of Diablo III book, and a 4 GB USB soulstone (including full versions of Diablo II and Diablo II: Lord of Destruction®) and corresponding Diablo skull base, as well as exclusive in-game content for Diablo III, World of Warcraft®, and StarCraft® II: Wings of Liberty®. Diablo III has received a Mature rating from the ESRB.