Thanks to ScootHawk for the info!

Sale 1:

https://backpack.tf/profiles/76561198196947639#!/compare/1527292800/1527379200

https://backpack.tf/profiles/76561198102349291#!/compare/1527292800/1527379200

https://cdn.discordapp.com/attachments/279880716718833666/468595127758225438/unknown.png

Sold for Steaming HWNM + 3 keys

HWNN Mini:

https://backpack.tf/suggestion/5b4d3554cf6c7551052ec69c

Suggestion for 19.5 keys

Total is 22.5 keys

Sale 2:

https://backpack.tf/profiles/76561198102349291#!/compare/1527552000/1528588800

Sold for 25 keys

Sale 3:

https://backpack.tf/profiles/76561198132182386#!/compare/1529366400/1529452800

Using there.

Sale 4:

https://backpack.tf/profiles/76561198190514893#!/compare/1529366400/1529452800

https://backpack.tf/profiles/76561198380701023#!/compare/1529366400/1529452800

Untrace.

Sale 5:

https://backpack.tf/profiles/76561198380701023#!/compare/1529539200/1529625600

https://backpack.tf/profiles/76561198226262240#!/compare/1529452800/1529539200

Sold for Planets Translator + ~2 keys in sweets

Translator Mini:

https://backpack.tf/suggestion/5b4d3abacf6c756317091a25

Suggestion for 12 keys.

Total is 14 keys.

Sale 6:

https://backpack.tf/profiles/76561198226262240#!/compare/1529452800/1529539200

https://backpack.tf/profiles/76561198065145332#!/compare/1529280000/1529539200

Sold for Aussie Flamethrower(~15) + ST Pool Party(28)

Total is 43 keys

Total sales @

14, 22.5, 25, 43

https://backpack.tf/classifieds?item=Forest%20Fire%20|%20Flame%20Thrower%20(Well-Worn)&quality=15&tradable=1&craftable=1&australium=-1&particle=704&killstreak_tier=0

Buyer for 18 keys.

Calling 43 the outlier.

Taking 23-25 keys.