I have a query that will sum of the net price on by each line item. Can I sum up everything, by quotenumber? Instead of two quieries, bring it into one?

Code:
SELECT     HDR.PlantNumber, HDR.QuoteNumber,   
               (ITM.NetUnitPrice + SUM(ISNULL(ITX.Adder, 0))) * ITM.Quantity * ITM.DiscountMultiplier AS QuoteNetValue
FROM         DataWarehouse.dbo.QuoteITX ITX RIGHT OUTER JOIN
                      DataWarehouse.dbo.QuoteITM ITM ON ITX.QuoteNumber = ITM.QuoteNumber AND ITX.PlantNumber = ITM.PlantNumber AND 
                      ITX.ItemNumber = ITM.LineItem RIGHT OUTER JOIN
                      DataWarehouse.dbo.QuoteHDR HDR ON ITM.PlantNumber = HDR.PlantNumber AND ITM.QuoteNumber = HDR.QuoteNumber
WHERE     (HDR.PlantNumber = '12' OR
                      HDR.PlantNumber = '18' OR
                      HDR.PlantNumber = '19' OR
                      HDR.PlantNumber = '22' OR
                      HDR.PlantNumber = '23') 
GROUP BY HDR.PlantNumber, HDR.QuoteNumber, HDR.YourInquiry, ITM.NetUnitPrice, ITM.Quantity, ITM.DiscountMultiplier
Results
[PlantNumber, QuoteNumber, NetValue]
5, 700, $50
5, 700, $75
5, 700, $25
5, 700, $50
5, 701, $10
5, 701, $10
5, 701, $10

New Results
[PlantNumber, QuoteNumber, NetValue]
5, 700, $200
5, 701, $30