You are buying a house and will borrow $215,000 on a 30-year fixed rate mortgage with monthly payments to finance the purchase. Your loan officer has offered you a mortgage with an APR of 4.45 percent. Alternatively, she tells you that you can buy down the interest rate to 4.20 percent if you pay points upfront on the loan. A point on a loan is 1 percent (one percentage point) of the loan value.

What are the most points you would be willing to pay to buy down the interest rate?