Mini for the Cloud 9 Lucky Shot - Micro for the Cloud 9 Bonk Boy

Blizzardy Storm Tyrant's Helm

Sale 1

Quicksold for pure

https://backpack.tf/profiles/76561198146924882#!/compare/1531872000/1531958400

https://backpack.tf/profiles/76561198317606171#!/compare/1531872000/1531958400

Sale 2

Sold for 22 keys

https://backpack.tf/profiles/76561198317606171#!/compare/1533859200/1533945600

https://backpack.tf/profiles/76561198071805624#!/compare/1533859200/1533945600

Sale 3

Sold for a Blizzardy Storm Modest Pile of Hat

https://backpack.tf/profiles/76561198024867201#!/compare/1530576000/1530662400

https://backpack.tf/profiles/76561198364735647#!/compare/1530662400/1530835200

Mini for the Modest Pile of Hat

https://backpack.tf/suggestion/5b8ab6a144325a621401193c

Taking 24.5 keys = 25 keys

Sale 4

Sold with 3 keys for a Cloud 9 Lucky Shot (used there)

https://backpack.tf/profiles/76561198364735647#!/compare/1530835200/1531267200

https://backpack.tf/profiles/76561198021055079#!/compare/1531094400/1531180800

Sale 5

Sold for 26 keys

https://backpack.tf/profiles/76561198021055079#!/compare/1531180800/1531267200

https://backpack.tf/profiles/76561198136792635#!/compare/1531267200/1531353600

Sale 6

Sold for a Purple Energy Sky High Fly Guy (still indate at 29 keys)

https://backpack.tf/profiles/76561198080179568#!/compare/1533513600/1533600000

https://backpack.tf/profiles/76561198113216284#!/compare/1533600000/1533686400

Sale 7

Bulk

https://backpack.tf/profiles/76561198113216284#!/compare/1533686400/1533772800

https://backpack.tf/profiles/76561198056080374#!/compare/1533686400/1533772800

Sale 8

Sold for 18 keys pure and ~8 keys in items= 26 keys

https://backpack.tf/profiles/76561198253093948#!/compare/1533427200/1533513600

https://backpack.tf/profiles/76561198207460065#!/compare/1533427200/1533513600

Sale 9

Quicksold to buy order

https://backpack.tf/profiles/76561198135386007#!/compare/1533340800/1533513600

https://backpack.tf/profiles/76561198315588518#!/compare/1533427200/1533513600

Sale 10

Untrace

https://backpack.tf/profiles/76561198315588518#!/compare/1534118400/1534204800

https://backpack.tf/profiles/76561198083720869#!/compare/1534118400/1534204800

Sale 11

https://marketplace.tf/items/99;5;u30

http://manic.tf/keyprice/?at=2018-08-02

Sold for $46.9 / $1.93 = 24.30 keys = 24 keys

Sales: 22 / 24 / 25 / 26 / 26 / 29

22 is pretty close to buyers, excluding. 29 is an obvious outlier and the Sky High Fly Guy can be expected to drop and becomes outdated pretty soon anyway, also excluding.

This leaves us with 24-26 keys.