The median home price in New Hampshire is $470,000. At 80% LTV, the typical loan is $376,000 at the current 7.00% average rate, producing a monthly P+I payment of $2,502. Total interest over 30 years at this rate: $524,553.
Property taxes in New Hampshire average 2.18% of assessed value, or $10,246 per year on the median home. This adds $854/month to your all-in housing cost. When evaluating a refinance, factor in property tax and insurance for a complete picture.
New Hampshire has no state income tax, so there is no state-level mortgage interest deduction. The federal deduction still applies on loans up to $750,000 for itemizers.