Cool to the Bone

https://backpack.tf/item/4082489537

Sale 1) Sold for a SS (87.5 Keys) + Ghosts Neckwear (81 Keys) + Nebula Hot Air (80 Keys) + GE Bonk Boy (39 Keys) + DBD Bomber's Bucket Hat (21 Keys)

https://backpack.tf/profiles/76561198195731583#!/compare/1497398400/1497484800

87.5 + 81 + 80 + 39 + 21 = 308.5, which I'll round to 310 Keys

https://backpack.tf/item/4005720952

Sale 2) Sold + Duped Cloudy Brainiac (178.5 Keys) for an Arcana HWNN (470 Keys)

https://backpack.tf/profiles/76561198101092551#!/compare/1497398400/1497571200

470 - 178.5 = 291.5 Keys, which I'll round to 290 Keys

Brainiac Mini

Sold for a Duped Bonzo Reggae (105 Keys) + Sunbeams Cowl (73.5 Keys)

https://backpack.tf/profiles/76561198030050182#!/compare/1493510400/1493596800

105 + 73.5 = 178.5 Keys