The board overseeing Oahu's rail transit project yesterday reluctantly agreed to nearly $6 million in added costs for the rail system. The money is needed to acquire dozens of properties by the end of the year and to ensure all the rail line's foundations are structurally sound. The move will allocate more than $3 million to provide three additional staffers, four acquisition agents and five relocation agents. About 159 properties still need to be bought to keep construction on schedule.