Salty and Shocky

https://backpack.tf/item/7001027798

Sale 1) Sold for 35 Keys

https://backpack.tf/profiles/76561198061489334#!/compare/1538784000/1538870400

Sale 2) Sold + 10 Keys for a Professional Killstreak Australium Rocket Launcher (~50 Keys)

https://backpack.tf/profiles/76561198376090993#!/compare/1540944000/1541030400

50 - 10 = 40 Keys

https://backpack.tf/item/6655528763

Sale 3) Sold + ~2 Keys of Items for 30 Keys

https://backpack.tf/profiles/76561198140959579#!/compare/1539734400/1540771200 - The Rocket was sold for 30 Keys

https://backpack.tf/profiles/76561198201196165#!/compare/1540512000/1540944000 - The 30 Keys were used to buy the Salty and Items

https://backpack.tf/profiles/76561198080179568#!/compare/1540857600/1540944000 - The 30 Keys then bought the Brown Bomber

Low outlier.

Sale 4) Sold for a Purple Energy Head Hedge (30.5 Keys) + 7 Keys

https://backpack.tf/profiles/76561198201196165#!/compare/1539907200/1539993600

https://backpack.tf/profiles/76561198043936328#!/compare/1539907200/1539993600

30.5 + 7 = 37.5, which rounds to 38 Keys

Hedge Mini

https://backpack.tf/suggestion/5c05edeb44325a6256070792 - 30.5 Keys