Marketplace Sales:

https://marketplace.tf/items/30067;5;u7

https://manic.tf/keyprice/?at=2019-01-18 - $60 / $1.75 = 34.29 keys

https://manic.tf/keyprice/?at=2019-01-22 - $55 / $1.75 = 31.43 keys

X = 34

X = 31

Other Sales:

https://backpack.tf/item/7282999731 (#1 & #2)

https://backpack.tf/item/6883814972 (#3 & #4)

https://backpack.tf/item/3366193453 (#5)

#1

Sold for unusual rocket launcher

https://backpack.tf/profiles/76561198127938353#!/compare/1548028800/1548115200

https://backpack.tf/profiles/76561198844852820#!/compare/1548028800/1548115200

Can be used to price the RL.

#2

Bulk-ish for another unusual rocket launcher

https://backpack.tf/profiles/76561198844852820#!/compare/1548115200/1548201600

https://backpack.tf/profiles/76561198080179568#!/compare/1548115200/1548201600

#3

Backpack purchase/transfer

https://backpack.tf/profiles/76561197960886327#!/compare/1543449600/1547078400

https://backpack.tf/profiles/76561198080996782#!/compare/1499385600/1543708800

#4

Bulk for pure

https://backpack.tf/profiles/76561198080996782#!/compare/1544400000/1544486400

https://backpack.tf/profiles/76561198232041512#!/compare/1544400000/1544486400

#5

Untraceable

https://backpack.tf/profiles/76561198061489334#!/compare/1546387200/1546473600

https://backpack.tf/profiles/76561198828872511#!/compare/1547164800/1547251200 - no good compare link

Sellers:

https://i.imgur.com/N6T6tdU.png

https://backpack.tf/item/7282999731 - 32 keys

https://backpack.tf/item/5376274676 - 40 keys

Sales at:

31

34

34 is too high given the month unsold at 32.

Going with 31 flat.