Sale #1:

https://backpack.tf/item/16174137425

https://backpack.tf/profiles/76561199564942025#!/compare/1757980800/1758067200

https://backpack.tf/profiles/76561198108020471#!/compare/1757980800/1759104000

on next we can see a group of 18 keys that match https://next.backpack.tf/profiles/76561198108020471/compare?from=1757980800&to=1759104000

Sale #2:

https://backpack.tf/profiles/76561198007904960#!/compare/1757980800/1758067200 ~ 4 ref matches

https://backpack.tf/profiles/76561199564942025#!/compare/1757980800/1758067200

Using next again we can see a group of 15 keys that match ( Near: 16175918408-16175918446 (15)) https://next.backpack.tf/profiles/76561199564942025/compare?from=1757980800&to=1758067200

Sale #3:

https://backpack.tf/item/16033037591 ~ mannco sale

Sale #4:

https://backpack.tf/item/15979161581

https://backpack.tf/profiles/76561198850121720#!/compare/1754784000/1754870400 ~ no matches

https://backpack.tf/profiles/76561198196622954#!/compare/1754784000/1754870400

Sale #5:

https://backpack.tf/profiles/76561198196622954#!/compare/1757721600/1757808000 ~ 28 keys match

https://backpack.tf/profiles/76561198055421322#!/compare/1757721600/1757808000

Sale #6:

https://backpack.tf/item/15969580379

https://backpack.tf/profiles/76561198053758441#!/compare/1754524800/1754784000 ~ no matches

https://backpack.tf/profiles/76561199422453221#!/compare/1754438400/1754870400 ~ 13 keys + 13 ref matches

Sale #7:

https://backpack.tf/item/15973616941

https://backpack.tf/profiles/76561199171483090#!/compare/1756598400/1757030400 ~ most likely 14 keys + 3.66 ref

https://backpack.tf/profiles/76561198109986831#!/compare/1756512000/1756598400

Sale #8:

https://backpack.tf/profiles/76561198822773578#!/compare/1756166400/1756252800 ~ no matches, SCM?

https://backpack.tf/profiles/76561199171483090#!/compare/1755302400/1756598400 ~ probably SCM

Sales @ 13, 14, 15, 18, 28

28 clear outlier, there is also an scm sale that supports another sale at 14 https://i.imgur.com/Kye2qmu.png / https://ibb.co/7xShxNSG

Taking 13-18.