A borrower secures a 10-year interest only loan for $500,000 at a rate of 6%. The loan is prepayable after year-5 for a fee that is the greater of yield maintenance or 5% of the outstanding principal balance. Rates have gone down to 4%, but the borrower wants to prepay the loan at the end of five years so he can sell the property. What is the prepayment penalty (rounded to the nearest $1,000)?