Create a price list comparison table

aitormadoz 

One way could be to CROSS JOIN price list of each SKU with itself and then computing the difference

Check this Power Query Solution. Please see attached file's Query Editor for steps

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUYoAYkMjpVgdCDcSxDWGc6NAXEM4NwTENdAzBQs4QXWbwXkgzQg5kF4TJLUgzeZKsbEA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [SKU = _t, PriceList = _t, Price = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"SKU", type text}, {"PriceList", type text}, {"Price", type number}}),
    #"Added Custom" = Table.AddColumn(ChangedType, "Comparison", each Table.SelectRows(ChangedType, (X)=>X[SKU] =[SKU])),
    #"Expanded Comparison" = Table.ExpandTableColumn(#"Added Custom", "Comparison", {"PriceList", "Price"}, {"Comparison.PriceList", "Comparison.Price"}),
    #"Added Custom1" = Table.AddColumn(#"Expanded Comparison", "Diff", each [Price]-[Comparison.Price])
in
    #"Added Custom1"

Here is an approach that will not require you to change the structure of your fact table.  You just need another table in your model to represent the comparison price list and then you can let DAX calculations do the rest.

With a model like the above, you can use the following calculation, using the recently added TREATAS function.

I have created a sample workbook here, that you can download: Download

Find out more about the TREATAS function here: https://docs.microsoft.com/en-us/dax/treatas-function

Comparison =
VAR varComparisonPrice =
    CALCULATE (
        MAX ( [Price] ),
        TREATAS (
            VALUES ( 'Comparison Price List'[Comparison Price List] ),
            'Price List'[Price List]
        )
    )
VAR varPrice =
    CALCULATE ( MAX ( [Price] ) )
RETURN
    varComparisonPrice - varPrice

You will get the result that you expect: