I think you're lowballing the figure: I imagine the real costs would be much higher. But I still believe that would have fit comfortably into the proposed total budget of $140 million allocated for Destiny's Xbox 360 development: http://www.develop-online.net/interview/revealed-the-huge-promises-and-secret-stipulations-of-the-bungie-activision-deal/0117411 At the very least, for an online-only game, this should have been the first thing discussed in development.