https://marketplace.tf/items/tf2/30839;5;u3001

Nov 22 - $12.71 / $1.75 = 7.26 keys

Nov 29 - $12.99 / $1.76 = 7.38 keys

Dec 16 - $12.99 / $2.02 = 6.43 keys

Jan 4 - $12.99 / $2.11 = 6.16 keys

Jan 18 - $13.99 / $2.11 = 6.63 keys

Jan 28 - $15.9 / $2.10 = 7.57 keys

Jan 30 - $15.9 / $2.10 = 7.57 keys

Feb 4 - $15.99 / $2.10 = 7.61 keys

https://backpack.tf/item/7567326010

https://backpack.tf/profiles/76561198134624832#!/compare/1605830400/1606608000

https://backpack.tf/profiles/76561198342161127#!/compare/1606521600/1606608000

Bulk

https://backpack.tf/profiles/76561198342161127#!/compare/1612483200/1612569600

https://backpack.tf/profiles/76561198141279750#!/compare/1612483200/1612569600

5 keys, 39.88 refined - rounds to 5.5 keys

https://backpack.tf/profiles/76561199084186813#!/compare/1606608000/1611360000

https://backpack.tf/profiles/76561198453530349#!/compare/1606521600/1606608000

Untraceable

https://backpack.tf/profiles/76561198453530349#!/compare/1607817600/1607904000

https://backpack.tf/profiles/76561198227321732#!/compare/1607817600/1607904000

Looks like bulk

https://backpack.tf/profiles/76561198061108999#!/compare/1611446400/1611532800

https://backpack.tf/profiles/76561199111821100#!/compare/1611187200/1611792000

Unique

https://backpack.tf/profiles/76561199111821100#!/compare/1612137600/1612483200

https://backpack.tf/profiles/76561198301897810#!/compare/1611619200/1612137600

Unique

https://backpack.tf/profiles/76561198382520065#!/compare/1608422400/1608595200

https://backpack.tf/profiles/76561198382520065#!/compare/1608422400/1608595200

Untraceable

https://backpack.tf/profiles/76561198031468760#!/compare/1609804800/1610150400

https://backpack.tf/profiles/76561198311498888#!/compare/1610064000/1610150400

Mega Strike Taunt: Didgeridrongo, which surprisingly has no backpack.tf price...

https://backpack.tf/profiles/76561198198440035#!/compare/1609200000/1609286400

https://backpack.tf/profiles/76561198146725636#!/compare/1608595200/1609286400

2 keys matches

https://backpack.tf/profiles/76561198146725636#!/compare/1609977600/1610150400

https://backpack.tf/profiles/76561198252924186#!/compare/1609459200/1610064000

Untraceable

https://backpack.tf/profiles/76561198454615761#!/compare/1606176000/1606262400

https://backpack.tf/profiles/76561198402009056#!/compare/1606089600/1606262400

Untraceable

https://backpack.tf/profiles/76561198402009056#!/compare/1607904000/1607990400

https://backpack.tf/profiles/76561198073381086#!/compare/1607990400/1608076800

Untraceable

https://backpack.tf/profiles/76561198056793444#!/compare/1611705600/1611792000

https://backpack.tf/profiles/76561198411392321#!/compare/1611705600/1611792000

5 keys, 33 refined - rounds to 5.5 keys

https://backpack.tf/profiles/76561198411392321#!/compare/1611878400/1612051200

https://backpack.tf/profiles/76561198209316908#!/compare/1607472000/1612224000

Untraceable

https://backpack.tf/profiles/76561198209316908#!/compare/1612310400/1612396800

https://backpack.tf/profiles/76561198173925222#!/compare/1612224000/1612310400

5 keys, 2 refined

https://backpack.tf/profiles/76561198171447086#!/compare/1605571200/1605657600

https://backpack.tf/profiles/76561198424960283#!/compare/1605484800/1605744000

6 keys

https://backpack.tf/profiles/76561198850178158#!/compare/1606780800/1606867200

https://backpack.tf/profiles/76561198070759453#!/compare/1606780800/1606867200

Bulk

Sales:

5

5.5

5.5

6

6.5

6.5

7.5

7.5

7.5

7.5

7.5

https://gyazo.com/858a60f198b34ec0d68cc9ae80ac6d67

Buyers 5.16 keys

seller for 6 days at 6 keys

Those 7.5 sales are hard to deny so let's go with 5.5-7.5