Making a pivot table

Well it depends on what the definition of lowest price is. If it is the price resulting from dividing sales by the number of units sold, then...

I'm working with this model structure:

To get the sales price by product for since the beginning of time:

Price by Product all years =
CALCULATE (
    DIVIDE ( SUM ( financials[ Sales] ), SUM ( financials[Units Sold] ) ),
    ALL ( 'Dates Table' )
)

and the lowest for all products

Lowest Sales Price all products = 
MINX(ALL('Product Table'[dProduct]), [Price by Product all years])

and finally the sales by month for the lowest selling price product 

Gross Sales for lowest Price Porduct =
SUMX (
    'Dates Table',
    CALCULATE (
        SUM ( financials[Gross Sales] ),
        FILTER (
            'Product Table',
            [Price by Product all years] = [Lowest Sales Price all products]
        )
    )
)

If you want to see the excercise by year...

Low price by year =
CALCULATE (
    DIVIDE ( SUM ( financials[ Sales] ), SUM ( financials[Units Sold] ) ),
    ALL ( 'Dates Table'[Month] )
)

Lowest price by Year = 
MINX(ALL('Product Table'[dProduct]), [Low price by year])

Gross Sales for lowest Price Porduct by year =
SUMX (
    VALUES ( 'Dates Table'[Month] ),
    CALCULATE (
        SUM ( financials[Gross Sales] ),
        FILTER ( 'Product Table', [Low price by year] = [Lowest price by Year] )
    )
)

Sample PBIX file attached