Sale 1:

https://backpack.tf/profiles/76561198179787957#!/compare/1564790400/1569715200

https://backpack.tf/profiles/76561198438270813#!/compare/1571702400/1572134400

Untrace

sale 2:

https://backpack.tf/profiles/76561198254988078#!/compare/1569974400/1570147200

https://backpack.tf/profiles/76561198002757046#!/compare/1571270400/1571356800

QS

Sale 3:

https://backpack.tf/profiles/76561198206068763#!/compare/1565913600/1569715200

https://backpack.tf/profiles/76561198342161127#!/compare/1565913600/1566086400

QS

Sale 4:

https://backpack.tf/profiles/76561198081807049#!/compare/1566518400/1566691200

https://backpack.tf/profiles/76561198254802111#!/compare/1566345600/1566518400

Sold with 15 keys for DBD Salty

use there

sale 5:

https://backpack.tf/profiles/76561198254802111#!/compare/1567641600/1567728000

https://backpack.tf/profiles/76561198054037654#!/compare/1567468800/1567728000

Sold for 18 keys

Sale 6:

https://backpack.tf/profiles/76561198113971364#!/compare/1566000000/1566259200

https://backpack.tf/profiles/76561198040275111#!/compare/1566172800/1566259200

Sold for 26 keys

Sale 7:

https://backpack.tf/profiles/76561198161953994#!/compare/1567814400/1567900800

https://backpack.tf/profiles/76561198337734785#!/compare/1567814400/1567900800

QS

sale 8:

https://backpack.tf/profiles/76561198337734785#!/compare/1568592000/1568678400

https://backpack.tf/profiles/76561198093658698#!/compare/1568678400/1568764800

Sold for 22 keys

Sale 9:

https://backpack.tf/profiles/76561198093658698#!/compare/1571702400/1571961600

https://backpack.tf/profiles/76561198817510262#!/compare/1571616000/1571702400

QS

Sale 10:

https://backpack.tf/profiles/76561198099467515#!/compare/1566345600/1566432000

https://backpack.tf/profiles/76561198085432135#!/compare/1566345600/1566432000

Sold for 15 keys

sale 11:

https://backpack.tf/profiles/76561198085432135#!/compare/1572134400/1572307200

https://backpack.tf/profiles/76561198337734785#!/compare/1572048000/1572134400

Sold for 13 keys (QS)

Sale 12:

https://backpack.tf/profiles/76561198155497026#!/compare/1566604800/1566691200

https://backpack.tf/profiles/76561198306319542#!/compare/1507161600/1567036800

untrace

sale 13:

https://backpack.tf/profiles/76561198306319542#!/compare/1567036800/1567382400

https://backpack.tf/profiles/76561198307920312#!/compare/1567641600/1568246400

Bulk

Sale 14:

https://backpack.tf/profiles/76561198307920312#!/compare/1568246400/1568332800

https://backpack.tf/profiles/76561198342161127#!/compare/1568160000/1568246400

Bulk

Sale 15:

https://backpack.tf/profiles/76561198168821894#!/compare/1564704000/1567209600

https://backpack.tf/profiles/76561198359850321#!/compare/1552348800/1565395200

Untrace

Sale 16:

https://backpack.tf/profiles/76561198359850321#!/compare/1552348800/1565395200

https://backpack.tf/profiles/76561198378408942#!/compare/1564012800/1565740800

Bulk

Sale 17:

https://backpack.tf/profiles/76561198378408942#!/compare/1566000000/1566172800

https://backpack.tf/profiles/76561198260686830#!/compare/1567036800/1567123200

Untrace

sale 18:

https://backpack.tf/profiles/76561198260686830#!/compare/1567123200/1567209600

https://backpack.tf/profiles/76561198067711632#!/compare/1565740800/1568505600

Untrace

sale 19:

https://marketplace.tf/items/tf2/30375;5;u61

$33.33 / $1.84 = 18.11 keys

total sales @:

13, 15, 18, 18, 22, 26 keys

buyers up to 17 keys,

sellers for ~19 keys,

unsolds at 20, 22 keys for months,

Taking 18 - 22 keys, conserving around unsolds.