Sale 1:

https://backpack.tf/profiles/76561198267903057#!/compare/1582934400/1583193600

https://backpack.tf/profiles/76561197964546925#!/compare/1582848000/1582934400

Untrace

sale 2:

https://backpack.tf/profiles/76561197964546925#!/compare/1583280000/1583366400

https://backpack.tf/profiles/76561198295486957#!/compare/1583280000/1583366400

QS

Sale 3:

https://backpack.tf/profiles/76561198295486957#!/compare/1583366400/1583452800

https://backpack.tf/profiles/76561198059021831#!/compare/1583366400/1583452800

Transfer

sale 4:

https://backpack.tf/profiles/76561198032080715#!/compare/1580947200/1581206400

https://backpack.tf/profiles/76561199003505433#!/compare/1580947200/1581033600

Bulk

sale 5:

https://backpack.tf/profiles/76561199028000687#!/compare/1583539200/1585526400

https://backpack.tf/profiles/76561198197292179#!/compare/1584748800/1585008000

Bulk

sale 6:

https://backpack.tf/profiles/76561198453530349#!/compare/1583539200/1583625600

https://backpack.tf/profiles/76561198153088409#!/compare/1583539200/1583712000

Sold for 9 keys

Sale 7:

https://backpack.tf/profiles/76561198060193542#!/compare/1581292800/1581379200

https://backpack.tf/profiles/76561198150552836#!/compare/1565481600/1586563200

Untrace

sale 8:

https://backpack.tf/profiles/76561198798977870#!/compare/1579824000/1579910400

https://backpack.tf/profiles/76561198341171690#!/compare/1579824000/1579910400

QS

sale 9:

https://backpack.tf/profiles/76561198341171690#!/compare/1584144000/1584230400

https://backpack.tf/profiles/76561198295486957#!/compare/1584144000/1584230400

Untrace

sale 10:

https://backpack.tf/profiles/76561198295486957#!/compare/1584144000/1584230400

https://backpack.tf/profiles/76561198059021831#!/compare/1584230400/1584316800

Transfer

Sale 11:

https://backpack.tf/profiles/76561198059021831#!/compare/1584316800/1584403200

https://backpack.tf/profiles/76561198143613491#!/compare/1583193600/1584489600

Bulk / untrace

sale 12:

https://backpack.tf/profiles/76561198245300992#!/compare/1585094400/1585353600

https://backpack.tf/profiles/76561198850274253#!/compare/1585180800/1585267200

Bulk

sale 13:

https://backpack.tf/profiles/76561198850274253#!/compare/1585440000/1585526400

https://backpack.tf/profiles/76561198346618954#!/compare/1585180800/1585785600

Untrace

sale 14:

https://backpack.tf/profiles/76561198129879465#!/compare/1580947200/1581120000

https://backpack.tf/profiles/76561198883676572#!/compare/1581033600/1581120000

Sold for Blizzardy Larrikin + 5 keys

use there

Sale 15:

https://backpack.tf/profiles/76561198883676572#!/compare/1581379200/1581724800

https://backpack.tf/profiles/76561198252237762#!/compare/1581379200/1581465600

sold for Blizzardy Airdog + 1 key

use there

Sale 16:

https://backpack.tf/profiles/76561198252237762#!/compare/1583107200/1583366400

https://backpack.tf/profiles/76561198363395191#!/compare/1583107200/1583193600

Sold for 9 keys (QS)

Sale 17:

https://marketplace.tf/items/tf2/31074;5;u127

$32.5 / $1.78 = 18.26 keys

$25.25 / $1.76 = 14.35 keys

$25.25 / $1.76 = 14.35 keys

$25 / $1.78 = 14.04 keys

$15.16 / $1.77 = 8.56 keys <--- https://backpack.tf/item/8181002169

$22.5 / $1.74 = 12.93 keys <--- https://backpack.tf/item/8153155753

$15.16 / $1.74 = 8.71 keys

$21.75 / $1.73 = 12.57 keys

$50.66 / $1.68 = 30.15 keys

$15.16 / $1.68 = 9.02 keys

$17.8 / $1.69 = 10.53 keys

$15.1 / $1.70 = 8.88 keys <--- https://backpack.tf/item/8164513918

$16.8 / $1.72 = 9.77 keys

$16.8 / $1.70 = 9.88 keys <--- https://backpack.tf/item/8181002169

$16.49 / $1.70 = 9.70 keys

$16.8 / $1.69 = 9.94 keys

$18.45 / $1.68 = 10.98 keys

$18.99 / $1.69 = 11.24 keys <--- https://backpack.tf/item/8168754488

$18.99 / $1.70 = 11.17 keys

$18.99 / $1.69 = 11.24 keys

$39.99 / $1.77 = 22.59 keys <--- https://backpack.tf/item/8219905304

Total sales @:

8.5, 8.5, 9, 9, 9, 9, 9.5, 9.5, 10, 10, 11, 11, 11, 11, 11, 13, 13, 14, 14, 14, 18, 23, 30 keys

buyers up to ~8.5 keys,

18 high,

taking the large range of 9 - 14 keys.