Joe bought a house for $300,000 and made a $60,000 down payment. He obtained a 20-year loan for the remaining amount. Payments were made monthly. The interest rate was 6%, compounded monthly. After 12 years (144 payments), he decided to refinance the loan at a current rate of 4.8%, compounded monthly. Given that Joe refinances over the remaining period of the original loan, the most he is willing to pay for refinance charges is closest to ... (4)