The Old Saybrook Board of Education on Tuesday evening voted to adopt a proposed $22,767,007 school district budget for next year. If approved by the Board of Finance and the town at referendum, the proposed plan would increase school spending by 4.53 percent. A significant driver of the proposed increase is higher costs to provide the federally-mandated appropriate education for special education students with extraordinary needs. Cuts in the state aid owed to the town under a special education grant formula also contributed to the higher costs.