Howard must decide if he will purchase discount points for his mortgage. Two discount points which cost 2% of the mortgage amount will result in a 0.5% decrease in the interest rate. The terms of the mortgage are shown below.

Howard's Mortgage

$423,000

30 year fixed

5% annual rate

0 discount points

M = $2,270.76

4.5% annual rate

2 discount points

M = $2,143.28

Howard plans to stay in his house for about five years. Should Howard purchase the two discount points? Explain your reasoning.