Surface area of the dome

$A = \frac{1}{2}\pi d^2 = \frac{1}{2}\pi (10^2)$

$A = 50\pi \, \text{ m}^2 = 50\pi \, \text{ m}^2 \left( \dfrac{100 \, \text{ cm}}{1 \, \text{ m}} \right)^2$

$A = 500\,000\pi \, \text{ cm}^2$

Amount to be paid for gold leaf

$C = 500\,000\pi (0.25)$

$C = \$392\,699.08$ *answer*