Exactly the same as it would take to create a new news organization, I expect.

I mean, we're all reading this as if the BBC is a "credit rating agency" of news, free from any vested interest or political bias, but of course that's not true: the BBC has a history of attacking financial institutions. It didn't create the problems in Northern Rock's business of course, but it is largely responsible for there being a run on that bank and it collapsing (the depositors were never actually in any risk due to government guarantees to all savers).