Dynamic Measure with Fieldparameters

showy could you please use beow updated measure to get correct Grand Total.

_Measure(Updated)2 = 
Var SelectedColumn = SELECTEDVALUE('PriceFields'[PriceColumn])

Var Result = 
SUMX(D_Item, 
    Var Quantity = CALCULATE(SUM(F_Sales[Quantity]))
    Var SelectedPrice = SWITCH (SelectedColumn,
                        "Price1", D_Item[Price1],
                        "Price2", D_Item[Price2],
                        "Price3", D_Item[Price3],
                        "Price4", D_Item[Price4],
                        BLANK())
    Var Result = Quantity * SelectedPrice //Final Result1
    Var Result2 = IF(ISBLANK(SelectedPrice), Quantity, Quantity * SelectedPrice) //Final Result2
    RETURN
    Result2 //Based on business needs chose any one result
    )
    
RETURN
Result 

Thanks,
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