SELECT j.JobId,
       ISNULL(SUM(p.Price * pn.Quantity), 0) AS Total
  FROM Jobs AS j
 INNER JOIN PartsNeeded AS pn ON pn.JobId = j.JobId
 INNER JOIN Parts AS p ON p.PartId = pn.PartId
 WHERE j.Status = 'Finished'
 GROUP BY j.JobId
 ORDER BY Total DESC, j.JobId