Saudi Arabia’s tab for using icons of western popular culture to enhance its stature and sway on the global stage could soon rise by another nine figures. The kingdom is reportedly willing to pay Argentinian maestro Lionel Messi $400 million-a-year for the twilight of his career. While a huge sum, even by football’s bloated standards, it’s just the latest in a string of moves by the petrostate’s rulers, who are plowing billions into sports, art and music.