Sale 1:

Sold for 29 keys

Seller: https://backpack.tf/profiles/76561198192602363#!/compare/1548028800/1548115200

Buyer: https://backpack.tf/profiles/76561198046960638#!/compare/1548028800/1548115200

https://backpack.tf/item/280211988

X = 29

Sale 2:

Sold in a day for 27 keys

Seller: https://backpack.tf/profiles/76561198337734785#!/compare/1552608000/1552694400

Buyer: https://backpack.tf/profiles/76561198158206236#!/compare/1552435200/1552694400

https://backpack.tf/item/206815321

X = 27

Sale 3:

Sold with ~5 keys in pure/items for Duped Logo Anger (Mini at 31 below)

Seller: https://backpack.tf/profiles/76561198124028596#!/compare/1553212800/1553299200

Buyer: https://backpack.tf/profiles/76561198060730062#!/compare/1553212800/1553299200

https://backpack.tf/item/633031752

X = 26

Marketplace Sales:

https://marketplace.tf/items/337;5;u7

https://manic.tf/keyprice/?at=2019-01-10 - $54 / $1.75 = 30.86 keys

X = 31

Other Sales:

https://backpack.tf/item/633031752 (#1 & #2)

https://backpack.tf/item/280211988 (#3)

https://backpack.tf/item/244457820 (#4)

https://backpack.tf/item/229016156 (#5-8)

https://backpack.tf/item/206815321 (#9)

#1

Untraceable

https://backpack.tf/profiles/76561198034207991#!/compare/1552176000/1552348800

https://backpack.tf/profiles/76561198124028596#!/compare/1552089600/1552176000

Most likely sold for the 29 keys on the buyer’s end, but I can’t confirm.

#2

Bulk for Scorching Birdcage

https://backpack.tf/profiles/76561198060730062#!/compare/1553299200/1553385600

https://backpack.tf/profiles/76561198182213262#!/compare/1553299200/1553385600

#3

Bulk for Duped Misty Ushanka

https://backpack.tf/profiles/76561198126484580#!/compare/1546560000/1546646400

https://backpack.tf/profiles/76561198192602363#!/compare/1546560000/1546646400

#4

Untraceable

https://backpack.tf/profiles/76561198049825208#!/compare/1553299200/1553385600

https://backpack.tf/profiles/76561198122604075#!/compare/1553299200/1553385600

Probably bulk for pure

#5

Bulk for Harvest Moon Billycock

https://backpack.tf/profiles/76561198116139337#!/compare/1547424000/1547510400

https://backpack.tf/profiles/76561198254620348#!/compare/1547337600/1547510400

#6

Bulk for Nebula Translator

https://backpack.tf/profiles/76561198254620348#!/compare/1547856000/1547942400

https://backpack.tf/profiles/76561198280357510#!/compare/1547856000/1547942400

#7

Untraceable

https://backpack.tf/profiles/76561198280357510#!/compare/1547856000/1547942400

https://backpack.tf/profiles/76561198091267840#!/compare/1547856000/1547942400

Only 23 keys match

#8

Sold with 2 keys for Circling TF Logo Hat of Cards

https://backpack.tf/profiles/76561198091267840#!/compare/1552694400/1552780800

https://backpack.tf/profiles/76561198094832204#!/compare/1552608000/1552694400

Only other sale on the Hat of Cards is untraceable, can be used to update the HoC instead.

#9

Untraceable

https://backpack.tf/profiles/76561198082587309#!/compare/1552608000/1552694400

https://backpack.tf/profiles/76561198337734785#!/compare/1552521600/1552608000

Duped Logo Anger Mini:

Sold for 31 keys

Seller: https://backpack.tf/profiles/76561198061440669#!/compare/1546732800/1546819200

Buyer: https://backpack.tf/profiles/76561198269446227#!/compare/1546732800/1546819200

https://backpack.tf/item/946686730

X = 31

Sellers:

https://i.imgur.com/Ftzy28U.png

https://backpack.tf/item/633031752 - 34 keys

https://backpack.tf/item/229016156 - 34 keys

https://backpack.tf/item/206815321 - 40 keys

Sales at:

26

27

29

31

27 sold in a day, and 26 went to a quickbuyer/is countered by current buyers. Excluding 26 & 27.

Going with 29-31.