Search same value in same table between two dates

[Anonymous]

I have one table which has my products. 

For each product finds if it was listed in a specific month in the past (the minimun of the date range, here lets say [oct, nov,dec,jan] with min = oct and current=jan) and score each product  as following:

1- Product present in both months 100 

2- If Newly listed then score is 50 

3- If was present in the reference period and not listed now then -50

I have only table  as follows

Date	Productid	price
1-Jan	1	10
1-Dec	1	20
1-Nov	1	30
1-Oct	1	40
1-Jan	2	10
1-Dec	2	12
1-Nov	2	13
1-Jan	3	12
1-Dec	3	14
1-Nov	3	15
1-Oct	3	29
1-Dec	4	14
1-Nov	4	15
1-Oct	4	29

Desired result shoul be 

Product	score
1	100
2	50
3	100
4	-50

I will appreciate your help

[amitchandak]

I converted month into date to work with

Measure = 
var _min = minx(all(Sheet1),Sheet1[Date])
var _max = maxx(all(Sheet1),Sheet1[Date])
var _before = CALCULATE(max(Sheet1[price]),filter((Sheet1),Sheet1[Date]=_min))
var _after = CALCULATE(max(Sheet1[price]),filter((Sheet1),Sheet1[Date]=_max))
Return
//maxx(VALUES(Sheet1[Productid]),_before & " "& _after)
if(ISBLANK(_after),-50,if(not(ISBLANK(_before)),100,50))

You can use first or last date of month

link: https://www.dropbox.com/s/kvazja8tnzqzq6a/samevalue.pbix?dl=0

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[Anonymous · Accepted solution]

@amitchandak Thank you very much.

It works as expected. Really thank you! this saves long hours of work