Use case

TRY
Code:
SELECT     tblOrder.internal_id, tblOrder.order_number,  tblItem.quantity, CASE WHEN tblItem.items_Id=1 THEN tblOrder.ship_cost ELSE 0 END as shipCost, 
FROM       tblOrder INNER JOIN
           items ON tblOrder.internal_id = tblOrder_Item_Bridge .order_Id INNER JOIN
           item ON tblOrder_Item_Bridge.items_Id = tblItem.items_Id
ORDER BY CASE WHEN tblItem.items_Id=1 THEN tblOrder.ship_cost
...