The Caldwell borough council this week voted to purchase a two-story professional building on Bloomfield Avenue and convert it to municipal offices, a move that should allow the town to get rid of the cramped metal trailers that are costing taxpayers $15,000 a month. Caldwell, looking to move forward from a failed downtown redevelopment plan that has left the town deeply in debt, has offered to buy the office building at 80 Bloomfield Avenue from Z&D Holding LLC for $2.7 million. The Caldwell council voted 5-to-0 for the purchase on Tuesday. Caldwell Mayor Garrett Jones said buying an existing…