Multiple new reports claim that the budget for Gears of War: E-Day was $500 million. Both Kotaku and Chris Dring of The Game Business reported today, with Kotaku’s report saying the number does not include marketing costs. Jez Corden of Windows Central added that the $500 million figure is not wrong, but his own sources aren’t able to say definitively if that number covers the game’s budget alone, or the game’s budget plus additional costs related to running the development…