Love of the game.

https://backpack.tf/item/5757464495

Sale 1) Quicksold for 22 Keys

https://backpack.tf/profiles/76561198163549413#!/compare/1499644800/1499731200

Sale 2) Quicksold for 23 Keys

https://backpack.tf/profiles/76561198202634258#!/compare/1499731200/1499817600

Sale 3) Sold + ~2 Keys of Items + 1 Key for a Duped Haunted Ghosts Swagman's Swatter (36.25 Keys)

https://backpack.tf/profiles/76561198177759574#!/compare/1499904000/1499990400

36.25 - 2 - 1 = 33.25, which rounds to 33 Keys

Swatter Mini

https://backpack.tf/profiles/76561198066195760#!/compare/1496793600/1496966400 - Sold for 38 Keys

https://backpack.tf/profiles/76561198079328856#!/compare/1495065600/1499731200 - Sold for a Nuts n' Bolts Rotation Sensation (34.5 Keys)

Sale 4) Quicksold for 25 Keys

https://backpack.tf/profiles/76561198128169326#!/compare/1499904000/1499990400

Sale 5) Sold + 23 Keys for a Strange Galactic Codex Captain Space Mann

https://backpack.tf/profiles/76561198263344996#!/compare/1500163200/1500249600 - Buyer's Backpack

High Outlier.

Sale 6) Sold for 18 Keys

https://backpack.tf/profiles/76561198263344996#!/compare/1500336000/1500422400

Low Outlier.

Sale 7) Sold for a Kill-a-Watt Towering Pillar of Hats (25 Keys) + 7 Keys

https://backpack.tf/profiles/76561198263344996#!/compare/1500336000/1500422400 - Seller's Backpack (shows the Keys)

https://backpack.tf/profiles/76561198087607344#!/compare/1500336000/1500422400 - Buyer's Backpack (shows the Pillar; the items sold for the Keys)

25 + 7 = 32 Keys

Sale 8) Sold for 22 Keys

https://backpack.tf/profiles/76561198087607344#!/compare/1500595200/1500681600

Sale 9) Sold + Circling Heart Airdog (26.5 Keys) for a Duped Purple Energy Chieftain's Challenge (62 Keys)

https://backpack.tf/profiles/76561198154253412#!/compare/1500940800/1501027200 - Seller's Backpack

https://backpack.tf/profiles/76561198205254623#!/compare/1500768000/1501027200 - Buyer's Backpack

62 - 26.5 = 35.5, which rounds to 36 Keys

Chieftain's Mini

https://backpack.tf/profiles/76561198025083656#!/compare/1498694400/1498780800 - Sold for a Strange Vivid Hot Dogger (50 Keys) + 15 Keys

https://backpack.tf/profiles/76561198154253412#!/compare/1501113600/1501200000 - Sold for 28 Keys + KaW Ballcap (19 Keys) + ~12 Keys of Items

Ballcap Micro

https://backpack.tf/suggestion/59965dd7cf6c753dc35846c5 - 19 Keys

Calling all of the pure quicksales/regular sales low because of the quicksales.