MDX - Calculate at lowest grain before rollup Problem

I am using MDX for some reporting. The idea is that we want all the customer ship to and SKU combinations that were sold in a particular period that were also sold in the same period the previous year. The period will usually be quarter but it could be month or week. There are also some parameters that show up in the WHERE statements. For each customer ship to and SKU combination there are calculations that we want to be performed at that level before they roll up to a taxonomy level. A SKU rolls up to a Taxonomy 4 which rolls up to a Taxonomy 3 which rolls up to a Taxonomy 2 which rolls up to a taxonomy 1. 

We are using a subcube to get the part of the cube that meet the parameter requirements and for customer ship to - SKU combinations that have sales in the same quarter this year and last year. Using that subcube I then roll up to Taxonomy 1 & 2. Here is the MDX:

With member measures.[LY Shipped Qty] as
(ParallelPeriod([Date - Reporting].[Reporting].[Year],1,[Date - Reporting].[Reporting].currentmember),[Measures].[Shipped Qty])

member measures.[LY_GP_Dev_and_Shltr] as [Measures].[LY GP Dev Amt]+[Measures].[LY GP Shelter Amt]
member measures.[GP_Dev_and_Shltr] as [Measures].[GP Dev Amt]+[Measures].[GP Shelter Amt]
member measures.[Cost_Change] as [Measures].[Shipped Qty]*(([Measures].[LY Sales Amt]-[Measures].[LY_GP_Dev_and_Shltr])/measures.[LY Shipped Qty])
member measures.[Price_Change] as [Measures].[Shipped Qty]*([Measures].[LY Sales Amt]/measures.[LY Shipped Qty])
member measures.[Cost_Vol_Var] as (measures.[LY Shipped Qty]-[Measures].[Shipped Qty])*(([Measures].[LY Sales Amt]-Measures.[LY_GP_Dev_and_Shltr])/measures.[LY Shipped Qty])
member measures.[Cost_rate_var] as ((([Measures].[LY Sales Amt]-measures.[LY_GP_Dev_and_Shltr])/measures.[LY Shipped Qty])-(([Measures].[Sales Amt]-measures.[GP_Dev_and_Shltr])/[Measures].[Shipped Qty]))*[Measures].[Shipped Qty]
member measures.[Price_Vol_Var] as  ([Measures].[Shipped Qty]-measures.[LY Shipped Qty])*([Measures].[LY Sales Amt]/[measures].[LY Shipped Qty])
member measures.[Price_Rate_Var] as (([Measures].[Sales Amt]/measures.[LY Shipped Qty]) - ([Measures].[LY Sales Amt]/[measures].[LY Shipped Qty])) * [Measures].[Shipped Qty]

select {[Shipped Qty],[Measures].[Sales Amt],measures.[GP_Dev_and_Shltr],[Measures].[LY Sales Amt],measures.[LY Shipped Qty],measures.[LY_GP_Dev_and_Shltr]
,measures.[Cost_Change],measures.[Price_Change],measures.[Cost_Vol_Var],measures.[Cost_rate_var]
,measures.[Price_Vol_Var],measures.[Price_Rate_Var]} 
on 0,
[Taxonomy].[Level 1].children*[Taxonomy].[Level 2].children on 1
from (
select
		  NONEMPTY(
					NONEMPTY([Current Customer].[Ship To Name].Children*[SKU - Known].[USN].children*[Taxonomy].[Taxonomy].[Level 1].&[1], [Measures].[Sales Amt]),[Measures].[LY Sales Amt]
				  )
		on 0
from [MY CUBE]
Where ([Date - Reporting].[Reporting].[Week].&[FY2012]&[12]&[51],[Brand Partner].[Brand Partner].&[15],[SKU - Known].[Exclusive Label].[All]
,[SKU - Known].[Import SKU].[All],[SKU - Brand - Known].[In Catalog].[All],[SKU - Brand - Known].[Call For Price].[All]
,[Current Customer].[National Account].[All],[Current Customer].[Group Name].[All])
 )
Where ([Date - Reporting].[Reporting].[Week].&[FY2012]&[12]&[51],[Brand Partner].[Brand Partner].&[15],[SKU - Known].[Exclusive Label].[All]
,[SKU - Known].[Import SKU].[All],[SKU - Brand - Known].[In Catalog].[All],[SKU - Brand - Known].[Call For Price].[All]
,[Current Customer].[National Account].[All],[Current Customer].[Group Name].[All])
;

You can see in the calculated members that some include division and multiplication. The problem we are facing is we want the calculation to happen at each Customer Ship To - SKU combination and then aggregate up. Instead it is summing up each part of the calculation then doing the calculation. So for the price change, instead of calculating price change for each Customer Ship To - SKU combination then aggregating up it is summing the shipped quantity, summing the LY sales amount and the LY shipped quantity then doing the multiplication and division. 

We tried opening up the SSAS database "hot" and tried scripting several iterations of SCOPE in the cube such as:

CREATE MEMBER CURRENTCUBE.[Measures].[Price_Change]
 AS [Measures].[Shipped Qty]*([Measures].[LY Sales Amt]/measures.[LY Shipped Qty]), 
FORMAT_STRING = "$#,##0.00;$-#,##0.00", 
NON_EMPTY_BEHAVIOR = { [Shipped Qty] }, 
VISIBLE = 1 ,  ASSOCIATED_MEASURE_GROUP = 'Sales'  ;

SCOPE ([Measures].[Price_Change],[Taxonomy].[Level 1].children,[Taxonomy].[Level 2].children);
[Measures].[Price_Change]= sum(
                                [Current Customer].[Ship To Name].Children*[SKU - Known].[USN].children*[Taxonomy].[Level 1].children*[Taxonomy].[Level 2].children
                                , [Measures].[Price_Change]
                               );
End Scope;

After each we would Save All and then try the MDX at the top with the calculated member for price change commented out so we could use the new measure we added to the cube. In all cases where we got something other than Error or null the calculation was still summing up the parts then doing the calculation.