Power Query Multiplying Aggregated field

Hi,
Workbook both examples attached.

I have added the summed values of one table into another and multiplied by a value in that table ;

 Table.AddColumn(Source, "Revenue", each
                          List.Sum( 
                  Table.SelectRows( #"Sales Table", (A)=> A[Item] = _ [Item] ) [Sales]
                                       )  
                            *[Price] )

And I've been trying to do, but using 'Merge', and then the Aggregate option from expand,; I can use List count and then change to sum,

   Table.AggregateTableColumn(#"Merged Queries", "Sales Table", {{"Sales", List.Sum ,    "Sum of Sales"}})

This gives me the sum of sales for each category, two things, I can then time this by 'price' column, two things can I is it possible to muliply by 'price' at this stage as in the first example, and is there a way to add data type within each aggregation?

I looked at MS docs and all I can see is a feature 'type table', is this the only way?


Richard.