Wally Bee purchased a new home for $600,000 with a $120,000 down payment. He financed the remainder with a 6% mortgage for 30 years. If Wally had originally planned on using a 15 year mortgage (also at 6% ), how much would Wally save in interest expense compared to the 30 -year mortgage? $321,190 $306,979 $348,927 $357,422