Making one Call of Duty costs up to $700 million. The shooter going viral right now costs $5, and no big studio will ever copy it, no matter how much money it makes. That $700 million number is real, by the way. It came out in Activision's own court filings. And the demand for a game like this was proven two decades ago. GTA San Andreas was literally gang territory wars in a fake LA. It sold 27.5 million copies and became one of the best-selling games of all time. Then every major studio…