There’s a great scene – there are many – in the American version of The Office where Warren Buffett is interviewed for a role by Jim Halpert. Buffett, showing some real thespian skills, negotiates his financial terms to the bemusement of the three-person interview panel. Halpert, as the chair, is rendered speechless when Buffett suggests the mileage rate of 25c is too low and asks for 27c!  There are various reasons why stars of all modes of entertainment shouldn’t represent themselves and why so few actually do. What that means, though, is that the agent, whatever the medium the star…