Sale 1:

https://backpack.tf/profiles/76561198297588602#!/compare/1560729600/1560902400

https://backpack.tf/profiles/76561198315110829#!/compare/1560816000/1560902400

Sold for Max Head(~22)

Liquid sold for keys, which were used to buy the Chieftain. Only thing that can match is the Max Head.

Sale 2:

https://backpack.tf/profiles/76561198134398243#!/compare/1562284800/1563494400

https://backpack.tf/profiles/76561198353483990#!/compare/1565481600/1566691200

Untrace

Sale 3:

https://backpack.tf/profiles/76561198082702453#!/compare/1567728000/1567987200

https://backpack.tf/profiles/76561198091502579#!/compare/1567900800/1567987200

Sold for 17 keys

Sale 4:

https://backpack.tf/profiles/76561198110988031#!/compare/1566950400/1567036800

https://backpack.tf/profiles/76561198394484957#!/compare/1566950400/1567036800

QS

Sale 5:

https://backpack.tf/profiles/76561198082415419#!/compare/1563062400/1568246400

https://backpack.tf/profiles/76561198190577279#!/compare/1564876800/1565136000

Untrace

Sale 6:

https://backpack.tf/profiles/76561198054198170#!/compare/1561248000/1561334400

https://backpack.tf/profiles/76561198069208168#!/compare/1561334400/1561507200

Sold for 14 keys + Strange G Fetti Warmer

Warmer Mini:

https://backpack.tf/suggestion/5d79e7b76780724e8f2c9775

Suggestion for 10.5 keys

Total is 24.5 keys

https://bot.tf/stats/listings/4WGXQENM

B/O of 24 keys, capping

Sale 7:

https://backpack.tf/profiles/76561198088702945#!/compare/1563753600/1564099200

https://backpack.tf/profiles/76561198165521629#!/compare/1563753600/1563840000

Sold for PE Elfin + ~2 keys in sweets

Elfin Mini:

https://backpack.tf/suggestion/5d834039678072798b40bdb9

Suggestion for 17 keys

Total is 19 keys

Sale 8:

https://backpack.tf/profiles/76561197961288175#!/compare/1567382400/1567814400

https://backpack.tf/profiles/76561198221525432#!/compare/1567468800/1567814400

Untrace

Sale 9:

https://marketplace.tf/items/tf2/31016;5;u111

$22 / $1.83 = 12.02 keys

Total sales @:

12, 17, 19, 22, 24 keys

buyers up to ~16 keys,

taking 17 - 24 keys