Area of Triangles · Hard problem

A banner shop charges $\$0.15$ per square inch for rectangular banners. Triangular banners cost $\$0.30$ per square inch, to account for the extra cutting, but they use only half the material of a rectangle with the same base and height. A triangular banner has a base of $24$ inches and a height of $10$ inches. How much MORE does a rectangular banner with the same base and height cost than this triangular banner, in dollars? (Use the rectangle's cost minus the triangle's cost; a negative answer means the rectangle is cheaper.)