Sale 1:

Sold for Pro. KS Strange Wrench (~10) + Didgeridrongo Unusualifier (~5)

Seller: https://backpack.tf/profiles/76561198359746121#!/compare/1583280000/1583366400

Buyer: https://backpack.tf/profiles/76561198057505460#!/compare/1583280000/1583366400

https://backpack.tf/item/7957328048

15 keys

Sale 2:

Sold for 11 keys

Seller: https://backpack.tf/profiles/76561198125706211#!/compare/1583971200/1584144000

Buyer: https://backpack.tf/profiles/76561198152767468#!/compare/1583971200/1584144000

https://backpack.tf/item/7957328048

11 keys

Sale 3:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198057505460#!/compare/1583625600/1583712000

Buyer: https://backpack.tf/profiles/76561198125706211#!/compare/1583020800/1583712000

https://backpack.tf/item/7957328048

10 keys

Marketplace Sales:

https://marketplace.tf/items/tf2/1093;5;u57

$17, Feb 22nd

No snapshots available.

https://backpack.tf/item/7957328048

http://manic.tf/keyprice?at=2020-02-22&price=17 - $17 / $1.78 = 9.55 keys

Rounds to 10 keys (average price of all sales is higher than 10, so we take the nearest integer)

Other Sales:

https://backpack.tf/item/7957328048 (#1 & #2)

https://backpack.tf/item/7957126880 (#3)

https://backpack.tf/item/7956802385 - marketplace

#1

Bulk for Orbiting Fire Cone

https://backpack.tf/profiles/76561198063409333#!/compare/1583193600/1583280000

https://backpack.tf/profiles/76561198359746121#!/compare/1583107200/1583193600

#2

Untraceable

https://backpack.tf/profiles/76561198152767468#!/compare/1584835200/1585008000

https://backpack.tf/profiles/76561198323565601#!/compare/1584748800/1584835200

Some ref matches

#3

Untraceable

https://backpack.tf/profiles/76561198878948902#!/compare/1582156800/1582243200

https://backpack.tf/profiles/76561198850274253#!/compare/1582156800/1582243200

Some ref matches

Sellers:

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

https://backpack.tf/item/7957126880 - ~12.3 keys

https://backpack.tf/item/7955821883 - ~12.3 keys

Sales at:

10 (2x)

11

15

15 is an outlier, and re-sold for much cheaper, which would invalidate the sale anyways. Excluding 15.

Taking 10-11.