Read the $500m is the investment in the whole franchise, including marketing, for their "10 year plan." Googled "bungie $500 million." So with 12m copies sold, they have made almost half of what they plan to spend back already. They have the cash to do more, but they would have to redo the game at this point to give us more IMO. I'm betting D2 will be different, but don't plan to preorder this time.