MARBLEHEAD – Marblehead taxpayers will save about $100,000 a year by refinancing the next 13 years of the 20-year, $25 million bond issue that funded the town?s new high school and rebuilt middle school. The savings will total $1.3 million.Thanks to the efforts of Town Administrator Tony Sasso, Treasurer Patricia Murray and Finance Director John McGinn, the town has taken advantage of a one-time opportunity to rebid the $15.86 million bond remaining on the 2004 bond issue. The low bidder was Janney Montgomery Scott with an interest rate of 2.28 percent, nearly half the 4.38 percent interest on the original bond issue seven years ago.Selectmen Chairman Jackie Belf-Becker called the savings “phenomenal.”Since the town finances its major capital projects through debt exclusion overrides, the $100,000 a year savings can?t be used by town departments in the operating budget – but the savings will reduce the amount taxpayers have to pay on the bond issue.