SELECT     ProdGruppe, MONTH(EffDatum) AS Month, YEAR(EffDatum) AS year, SUM( _
  Preis) AS Kosten, SUM(ABS(BewegMenge)) AS Qty
FROM         BackFl
WHERE     (ProdGruppe LIKE 'G%')
GROUP BY ProdGruppe, YEAR(EffDatum), MONTH(EffDatum)
ORDER BY Month, year, ProdGruppe