Using sales that were less than a month old when I started making this suggestion (26/9)

Sales 1-4:

Sold for $34.99, $27.25, $22.80, & $30.86

https://marketplace.tf/items/30922;5;u3006

http://manic.tf/keyprice/?at=2018-08-27 - $30.86 / $1.89 = 16.33 keys

http://manic.tf/keyprice/?at=2018-09-03 - $22.8 / $1.89 = 12.06 keys

http://manic.tf/keyprice/?at=2018-09-03 - $27.25 / $1.89 = 14.42 keys

http://manic.tf/keyprice/?at=2018-09-19 - $34.99 / $1.85 = 18.91 keys

https://backpack.tf/item/6715730203 - No B/O

https://backpack.tf/item/6498101805 - No B/O

https://backpack.tf/item/6457837201 - No B/O

Can’t find the other one.

X = 19

X = 16

X = 14

X = 12

Sale 5:

Sold for 15 keys + ~3 keys in items

Seller: https://backpack.tf/profiles/76561198202186637#!/compare/1538092800/1538179200

Buyer: https://backpack.tf/profiles/76561198334592679#!/compare/1519171200/1538697600

https://backpack.tf/item/6457837201

X = 18

Sale 6:

Sold to a bot for 14 keys + 14 ref

Seller: https://backpack.tf/profiles/76561198801119167#!/compare/1538524800/1538611200

Buyer: https://backpack.tf/profiles/76561198312583107#!/compare/1538524800/1538611200

https://backpack.tf/item/6507329384

X = 14

Other Sales:

https://backpack.tf/item/6459427711 (#1)

https://backpack.tf/item/6457837201 (#2 & #3)

https://backpack.tf/item/6797602110 - not unusual at the time

https://backpack.tf/item/6507329384 - not unusual at the time

https://backpack.tf/item/6479234449 - SCM

#1

Bulk for pure

https://backpack.tf/profiles/76561197964546925#!/compare/1536969600/1537056000

https://backpack.tf/profiles/76561198334598690#!/compare/1536969600/1537056000

https://i.imgur.com/6Pb15mS.png - Labelled as 15 keys

#2

Bulk

https://backpack.tf/profiles/76561198202186637#!/compare/1537833600/1537920000

https://backpack.tf/profiles/76561198202186637#!/compare/1537833600/1537920000

#3

Untraceable

https://backpack.tf/profiles/76561198334592679#!/compare/1538870400/1539216000

https://backpack.tf/profiles/76561198305676157#!/compare/1538870400/1538956800

https://i.imgur.com/HUW8bGG.png - labelled as 14 keys + 2.11 ref

Sellers:

https://i.imgur.com/AP4zIBY.png

https://backpack.tf/item/6904186082 - 17 keys

https://backpack.tf/item/6457837201 - 19 keys

https://backpack.tf/item/6507329384 - 21 keys

https://backpack.tf/item/6459427711 - 22 keys

Sales at:

12

14 (2x)

16

18

19

12 is an outlier, excluding.

Worth noting that at the time I started making this suggestion, there were more than 1 buyer at ~14 keys, and there was only 1 sale at around 14 keys. Had I created the suggestion back then, I would’ve excluded 14. Now, it can be seen as a common trading point, with weak proof against 14. Keeping 14. https://i.imgur.com/AAynnVc.png

Going with 14-19.