Listing 3: Query That Returns Composite Plan Cost Savings
DECLARE @varPlan varchar(20)
SET @varPlan = 'SuperDooperPlan B'
SELECT   ServiceName AS "Plan Name",
   '$ '+cast(UnitPrice AS char(4)) 
     AS "Plan Price",
   '$ '+cast( UnitPrice - (SELECT sum(unitprice) FROM Service INNER JOIN 
   ServiceComponent
      ON ServiceID = ComponentID
            WHERE AssemblyID = (SELECT ServiceID 
              FROM Service
              WHERE ServiceName = @varPlan)) AS char(4)) 
                AS "Cost Savings"
FROM service
WHERE ServiceName = @varPlan