A movie poster is 3 feet wide and 6 feet tall. A frame shop charges $2.00 per foot for a black metal frame. How much would it cost to buy a black metal frame for the movie poster?

The perimeter of the poster is 3+3+6+6=18 feet.

Therefore, it would cost $2.00 x 18 = $<<2*18=36.00>>36.00 to buy a black metal frame for the movie poster. Answer: \boxed{36}.