Algo así te quedaría con el nombre de GRUPO y para que te de el Stock tendrías que especificar que ALMACÉN.
select OITM.itemcode, OITM.itemname, OITM.ItmsGrpCod, OITM.AvgPrice as 'COSTO', OITM.U_SEI_LINEA AS 'LINEA', OITM.U_SEI_FAMILIA AS 'FAMILIA', OITM.U_SEI_SUB_FAMILIA AS 'SUB_FAMILIA', OITB.ItmsGrpNam, OITW.OnHand
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=2 AND ItemCode=OITM.ItemCode) AS MESON
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=3 AND ItemCode=OITM.ItemCode) AS BRONCE
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=4 AND ItemCode=OITM.ItemCode) AS PLATA
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=5 AND ItemCode=OITM.ItemCode) AS ORO
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=6 AND ItemCode=OITM.ItemCode) AS DISTRIBUIDORES
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=7 AND ItemCode=OITM.ItemCode) AS HOLDING
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=8 AND ItemCode=OITM.ItemCode) AS FUNCIONARIOS
,(SELECT PRICE FROM ITM1 WITH(NOLOCK) WHERE PriceList=10 AND ItemCode=OITM.ItemCode) AS PPM
FROM OITM with(nolock) INNER JOIN OITB ON OITM.[ItmsGrpCod] = OITB.[ItmsGrpCod]
INNER JOIN OITW ON OITM.ItemCode = OITW.ItemCode
WHERE OITW.WhsCode='numero almacen'