https://marketplace.tf/items/tf2/183;5;u61

Jan 26 - $29.99 = 17 keys

Feb 15 - $27.95 = 16 keys

Feb 28 - $28.00 = 15 keys

https://backpack.tf/item/1793668831

https://backpack.tf/item/7956372851

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https://backpack.tf/profiles/76561198311498888#!/compare/1577577600/1577664000

https://backpack.tf/profiles/76561198046164626#!/compare/1577577600/1577664000

11 keys + 20 refined from stn.tf, near id 8377915399 in first compare link

//

https://backpack.tf/profiles/76561198328629740#!/compare/1582156800/1582243200

https://backpack.tf/profiles/76561198041536305#!/compare/1582243200/1582329600

Bulk

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https://backpack.tf/profiles/76561198328629740#!/compare/1582588800/1582675200

https://backpack.tf/profiles/76561198252918994#!/compare/1582588800/1582675200

14 keys

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https://backpack.tf/profiles/76561198344291072#!/compare/1580428800/1580515200

https://backpack.tf/profiles/76561198286581911#!/compare/1580515200/1580860800

Valiant Vortex Bat Hat, which is pretty much looking to be 11-12 keys, which is under buyers on the Drill Hat

https://gyazo.com/0e374362879010f40d41dbfc0ab98936

https://gyazo.com/0735dcf4b380c95c4a2db855c2a1338b

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https://backpack.tf/profiles/76561198286581911#!/compare/1582329600/1582588800

https://backpack.tf/profiles/76561198129097160#!/compare/1582502400/1582588800

Double Spelled Genuine Killer Exclusive, which previously sold for 14 keys

https://backpack.tf/profiles/76561198157350531#!/compare/1581120000/1581552000

https://backpack.tf/profiles/76561198129097160#!/compare/1574467200/1581379200

Which ends up under buyers again for the Drill Hat

https://gyazo.com/0735dcf4b380c95c4a2db855c2a1338b

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https://backpack.tf/profiles/76561198129097160#!/compare/1582588800/1582848000

https://backpack.tf/profiles/76561198057496070#!/compare/1582416000/1582848000

I'm unsure if the Genuine Badge was involved, but if it wasn't, then it's under buyers

//

https://backpack.tf/profiles/76561198110748059#!/compare/1580083200/1580256000

https://backpack.tf/profiles/76561198363395191#!/compare/1580169600/1580256000

13 keys + 3 refined, under buyers

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https://backpack.tf/profiles/76561198126947267#!/compare/1578787200/1578873600

https://backpack.tf/profiles/76561198080179568#!/compare/1578700800/1578787200

Untraceable

//

https://backpack.tf/profiles/76561198190714350#!/compare/1579564800/1579737600

https://backpack.tf/profiles/76561198080179568#!/compare/1579651200/1579737600

14 keys + 37 refined, near id 8447168719 in 2nd compare link

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https://backpack.tf/profiles/76561198190714350#!/compare/1579996800/1580083200

https://backpack.tf/profiles/76561198142892266#!/compare/1579910400/1579996800

Bulk

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https://backpack.tf/profiles/76561198142892266#!/compare/1579996800/1580083200

https://backpack.tf/profiles/76561198255568360#!/compare/1579996800/1580083200

Bulk, gambling, untraceable

//

https://backpack.tf/profiles/76561198255568360#!/compare/1580169600/1580256000

https://backpack.tf/profiles/76561198134546405#!/compare/1580169600/1580256000

Bulk, gambling, untraceable

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https://backpack.tf/profiles/76561198087494715#!/compare/1582329600/1582416000

https://backpack.tf/profiles/76561198100644790#!/compare/1582329600/1583280000

Bulk, gambling, untraceable

//

https://backpack.tf/profiles/76561198878866368#!/compare/1582502400/1582761600

https://backpack.tf/profiles/76561198100644790#!/compare/1582329600/1583280000

Untraceable

//

Sales:

11-12

13

13

14

14

14+37ref

15

16

17

7 buyers at 14 keys

https://gyazo.com/4875b4854e0d8798059f495c7921bdef

if I exclude 14, I lose 5/9 of my data points

Going with 14-17 keys :/