Update!

Sale 1: https://backpack.tf/profiles/76561198400192243#!/compare/1572739200/1573430400

https://backpack.tf/profiles/76561198080179568#!/compare/1573344000/1573430400

5 keys + ref it seems

Sale 2: https://backpack.tf/profiles/76561198080179568#!/compare/1574812800/1574985600

https://backpack.tf/profiles/76561198312441398#!/compare/1574899200/1574985600

?

Sale 3: https://backpack.tf/profiles/76561198372681544#!/compare/1575072000/1575158400

https://backpack.tf/profiles/76561198037674114#!/compare/1574467200/1575244800

?

Sale 4: https://backpack.tf/profiles/76561198208827912#!/compare/1576540800/1576627200

https://backpack.tf/profiles/76561198872628170#!/compare/1576540800/1576627200

Sum bulk.

Sale 5: https://backpack.tf/profiles/76561198872628170#!/compare/1576627200/1576800000

https://backpack.tf/profiles/76561198161662927#!/compare/1576627200/1576713600

?

Sale 6: https://backpack.tf/profiles/76561198161662927#!/compare/1577232000/1577318400

https://backpack.tf/profiles/76561198385893455#!/compare/1577232000/1577318400

The users may be related, this sale is a untrace

Sale 7: https://backpack.tf/profiles/76561198385893455#!/compare/1577232000/1577318400

https://backpack.tf/profiles/76561198366515751#!/compare/1577232000/1577318400

?

Sale 8: https://backpack.tf/profiles/76561198366515751#!/compare/1577232000/1577318400

https://backpack.tf/profiles/76561198411506431#!/compare/1575676800/1577404800

?

Sale 9: https://backpack.tf/profiles/76561198411506431#!/compare/1577404800/1577491200

https://backpack.tf/profiles/76561198295486957#!/compare/1577318400/1577404800

?

Sale 10: https://backpack.tf/profiles/76561198142090071#!/compare/1570752000/1571011200

https://backpack.tf/profiles/76561198411254016#!/compare/1571011200/1571097600

Sold for a Skill Gotten Gains Taunt: Skullcracker (4.5 keys) + a key

4.5 + 1 = 5.5

Sale 11: https://backpack.tf/profiles/76561198821294885#!/compare/1570752000/1571011200

https://backpack.tf/profiles/76561198411254016#!/compare/1571011200/1571097600

Sold with 1 key for a Terror-Watt Trash Man (9.5 keys)

9.5 - 1 = 8.5

Mini for the Trash: https://backpack.tf/suggestion/5e0805e8720dc42e650f959f

Sale(s): 8.5. Classies: https://i.imgur.com/fLRirEL.png. 8.5 flat for now, anyway.