I am trying to graph savings for each category- this is done by calculating the minimum "new" price for a part, subtracting it from the original price and  multiplying it by the quantity. There  are multiple unique  parts in each category, however each part may have several "new" prices that suppliers have offered. Created a formula that finds the minimum price for a part and calculates the savings which works in a text table... HOWEVER if two or more suppliers have offered the SAME "new" price, the graph double counts them.

I have tried without success 

-Creating a Set for each category and summing the values for the set

-{ FIXED [Category] : [Total Savings]) }