A borrower has secured a 30 year, $189,000 loan at 4% with monthly payments. Fifteen years later, an investor wants to purchase the loan from the lender. If market interest rates are 6%, what would the investor be willing to pay for the loan (assuming the investor believes that all remaining payments will be paid as scheduled)?

What is the effective cost of a combination of an 80% mortgage at 3% and a second mortgage (for 10% of the purchase price) at 4%? Both mortgages carry a 30-year term and have no points/closing costs.