Sale 1:

https://backpack.tf/profiles/76561198045232326#!/compare/1580860800/1580947200

https://backpack.tf/profiles/76561198169130112#!/compare/1580860800/1580947200

Untrace

Sale 2:

https://backpack.tf/profiles/76561198169130112#!/compare/1581033600/1581638400

https://backpack.tf/profiles/76561198382267048#!/compare/1586044800/1586131200

Untrace

Sale 3:

https://backpack.tf/profiles/76561198382267048#!/compare/1586131200/1586217600

https://backpack.tf/profiles/76561198153657886#!/compare/1585699200/1586563200

Untrace

Sale 4:

https://backpack.tf/profiles/76561198332172321#!/compare/1581724800/1581897600

https://backpack.tf/profiles/76561198375290326#!/compare/1581811200/1581897600

Sold with ~3.5 keys in sweets for P Fetti Hermes

hermes Mini:

https://backpack.tf/suggestion/5ea6aed8259c7b127966bea2

Suggestion for 12 keys

Total is 15.5 keys

sale 5:

https://backpack.tf/profiles/76561198375290326#!/compare/1581897600/1581984000

https://backpack.tf/profiles/76561198084219943#!/compare/1581897600/1581984000

Sold with ~3.5 keys in sweets for OF Toy soldier

use there

sale 6:

https://backpack.tf/profiles/76561198084219943#!/compare/1581984000/1582070400

https://backpack.tf/profiles/76561198152648165#!/compare/1581984000/1582070400

Sold for 7 keys

sale 7:

https://backpack.tf/profiles/76561198152648165#!/compare/1582070400/1582156800

https://backpack.tf/profiles/76561198974289370#!/compare/1582070400/1582156800

Untrace

Sale 8:

https://backpack.tf/profiles/76561198974289370#!/compare/1582329600/1582416000

https://backpack.tf/profiles/76561198838447026#!/compare/1582329600/1582416000

QS

sale 9:

https://backpack.tf/profiles/76561198838447026#!/compare/1583020800/1583107200

https://backpack.tf/profiles/76561198118334867#!/compare/1582848000/1583193600

Sold for ~7 keys

sale 10:

https://backpack.tf/profiles/76561198118334867#!/compare/1582848000/1583193600

https://backpack.tf/profiles/76561198125791160#!/compare/1583107200/1583193600

Bulk

Sale 11, 12:

https://marketplace.tf/items/tf2/732;5;u30

$16.5 / $1.69 = 9.76 keys

$15 / $1.69 = 8.88 keys

Total sales @:

7, 7, 9, 10, 15.5 keys

buyers up to 6.5 keys,

seller at 10 keys, unsold for 2 months:

https://i.imgur.com/57r3izT.jpg

taking 7 - 10 keys.