Calculate the saving made on historic purchased items

[lolita94]

Hello everyone ,

I would like to get your help for the following:

This table shows the items that have been purchased during the year. My objective is calculate how many we saved when we purchased each item (I'm trying to compare each time the price of the last purchase with the current one).

Purchase Order	Date	Item	Quantity	Price
A156	12/01/2018	A	12	1.2
A597	05/02/2018	B	5	25.1
A856	01/03/2018	D	6	13.75
A251	28/04/2018	E	2	150
A987	30/04/2018	A	1	0.95
A302	12/05/2018	C	10	89.57
A201	25/06/2018	B	9	22.65
A875	19/07/2018	A	7	0.75
A935	21/08/2018	E	3	135
A156 <tbody> </tbody>	11/09/2018	C	5	89.57
A307	23/10/2018	D	15	11.5

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I tried to get the first purchase date for each item and the price :

Item	First purchase date	Price
A	12/01/2018	1.2
B	05/02/2018	25.1
D	01/03/2018	13.75
E	28/04/2018	150
A	30/04/2018	0.95
C	12/05/2018	89.57

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I put in the 2nd column :

=MIN(IF(Tableau1[Item]=Feuil2!A2;Tableau1[Date])) (Ctrl+Shift+enter)

And for the last column :

=SUMIFS(Tableau1[Unit Price];Tableau1[Item];Feuil2!A2;Tableau1[Date];Feuil2!B2)


I need to go back again to my initial table to calculate the price difference between each line and the last purchase price to see how we save each time.

The problem is I need to know how we saved when the item is repeated for the 3rd time, for example item 'A' we saved (1.2-0.95=0.25)

I need to capture the next saving which is (0.95-0.75=0.2); the same thing for all the lines on my initial table.

Is there a way to do it only with formulas or do I need to use VBA coding ?

Thank you in advance.