Your firm recently paid a dividend of $4 to common stockholders. Dividends are expected to grow at 8% per year for the foreseeable future. The current stock price is $54. New shares could be sold for the same price, but flotation costs would amount to $6 per share. Also, the firm can issue 20-year, $1,000 par bonds at a pre-tax cost of 11.4%. The firm's tax rate is 34%. What is the firm's cost of capital if their capital structure consists of 60% external equity and 40% bonds?