Measure to Sum Values of Another Measure Aggregated is a Summary Table

[ChrisW3]

I have a model based on inventory issue transactions. I have one measure that calculates a monthly average of items issued from inventory. I have another measure that does that same thing, but filters based on a second calendar table I created with an inactive relationship to the inventory transactions table so I can have 2 date slicers to select 2 different date periods to compare the monthly averages between 2 periods. I also have another measure that calculates an average item price, and I want to take the difference in monthly average quantities multiplied by the average price to get a total $ variance. Where I'm having trouble is getting that calculated total $ variance to total up the way I want it. I want it to calculate the $ variance per inventory item number, but then sum the values of that measure rather than use the same calculation across all the items in aggregate. Here are my measures:

Total Issues = SUM([QTY_IN_EACH])

Number of Months = DISTINCTCOUNT(Issues_All[YearMonth])

Monthly Average = [Total Issues]/[Number of Months]

Monthly Average - Comparison Period = CALCULATE([Monthly Average],ALL('Calendar'),USERELATIONSHIP(Issues_All[I-Date],'Calendar Reference'[Date-Comparison]))

Change from Comparison Period = [Monthly Average]-[Monthly Average - Comparison Period]

Average Unit Cost = SUMX(Issues_All,[UNIT_PRICE_PER_EACH]*[QTY_IN_EACH])/SUMX(Issues_All,[QTY_IN_EACH])

Change from Comparison Period - Extended per Average Unit Cost = [Change from Comparison Period]*[Average Unit Cost]

How do I write a measure that will calculate that last measure per [ITEM_NO], then take those values for each item and them sum them? This image is what I currently have, and I want the Card that currently shows 90,242.99 to show $40,865.76, which is the sum of the values displayed in the last column of the table (the last DAX measure in the list I provided above).

Current draft visual

[AllisonKennedy]

Is your Average Unit Cost Total what you expect? Using a SUMX in that last measure may be the key to your success.

See if this helps any:
https://community.powerbi.com/t5/DAX-Commands-and-Tips/Dealing-with-Measure-Totals/td-p/63376

[ChrisW3]

I do think SUMX is the way to go, however I've tried 2 different variations and neither is giving desired result:

SUMX ( VALUES ( Issues_All[ITEM_NO] ), [Change from Comparison Period - Extended per Average Unit Cost] )

SUMX(SUMMARIZE(Issues_All[Item No],"Total Difference",[Change from Comparison Period - Extended per Average Unit Cost]),[Total Difference])