Thank you very much to everyone who helped in the comments of the last one :)

Sale 1 :

https://marketplace.tf/items/tf2/30116;5;u61 // no history found , thank you very much for those who tried finding

15th August on marketplace : 37/1,81 = 20,4 , i'll round down to 20

Sale 2 :

Sold for 18 keys pure 13th of september

https://backpack.tf/item/9049505008

https://imgur.com/a/WI0Qgcj

Sale 3 :

https://imgur.com/a/xdGWBG7 | https://backpack.tf/item/3473264568

bought for 27 euro , avg keys on 8th october were 1.87 , so 14.44 , round down to 14 , thanks to Xergoyf