Sale 1:

Sold for 28 keys

Seller: https://backpack.tf/profiles/76561198011321852#!/compare/1558915200/1559001600

Buyer: https://backpack.tf/profiles/76561198199425379#!/compare/1558828800/1559001600

https://backpack.tf/item/4055855598

X = 28

Sale 2:

Sold for Strange Spec. KS Kritzkrieg (~21) + ~4 keys in pure/items

Seller: https://backpack.tf/profiles/76561198280357510#!/compare/1560556800/1560643200

Buyer: https://backpack.tf/profiles/76561198351184262#!/compare/1560556800/1560643200

https://backpack.tf/item/4055855598

https://steamcommunity.com/market/listings/440/Strange%20Spirit%20of%20Halloween%20War%20Paint%20%28Field-Tested%29 - war paint at around half a key, other items help round it to a key.

Spec. KS Kritz Sellers are at ~24, which is significantly higher than non-ks. Using non-ks.

Non ks kritz: https://backpack.tf/suggestion/5d2d263867807263cc093960

X = 25

Sale 3:

Sold to a bot for 22 keys + 10 ref

Seller: https://backpack.tf/profiles/76561198140565712#!/compare/1559606400/1559692800

Buyer: https://backpack.tf/profiles/76561198282471428#!/compare/1559606400/1559692800

https://backpack.tf/item/4055855598

X = 22

Other Sales:

https://backpack.tf/item/4055855598

#1

Untraceable, only 9 keys match

https://backpack.tf/profiles/76561198199425379#!/compare/1559520000/1559692800

https://backpack.tf/profiles/76561198140565712#!/compare/1559606400/1559692800

probably sold for 22 keys on the buyer’s end.

#2

Sold with 5 keys for Burning Brain-Warming Wear

https://backpack.tf/profiles/76561198282471428#!/compare/1559606400/1559692800

https://backpack.tf/profiles/76561198280357510#!/compare/1559606400/1559692800

Would end up being lower than quickbuyers if used here, given current sellers on the brain.

#3

Bulk for Clairvoyance Defragmenting Hard Hat

https://backpack.tf/profiles/76561198351184262#!/compare/1561507200/1561766400

https://backpack.tf/profiles/76561198089253101#!/compare/1561680000/1561766400

Sales at:

22

25

28

No current sellers.

22 quicksold to a bot, excluding 22.

Going with 25-28.