Rowdy Rouser

https://backpack.tf/item/3708332880

Sale 1) Sold for 27 Keys

https://backpack.tf/profiles/76561198313538268#!/compare/1550361600/1550534400

Sale 2) Sold for 23 Keys

https://backpack.tf/profiles/76561197978439752#!/compare/1551052800/1551484800

Low outlier.

Sale 3) Sold for 28 Keys

https://backpack.tf/profiles/76561198313538268#!/compare/1554681600/1554768000

https://backpack.tf/item/3387719453

Sale 4) ?

https://backpack.tf/profiles/76561198161481285#!/compare/1556236800/1556409600

https://backpack.tf/profiles/76561198121026492#!/compare/1555113600/1556409600

Sale 5) Sold for an Eerie Orbiting Fire Reggaelator (25 Keys) + 1 Key

https://backpack.tf/profiles/76561198121026492#!/compare/1555113600/1556409600

https://backpack.tf/profiles/76561198132527164#!/compare/1556323200/1556409600

25 + 1 = 26 Keys

Reggae Mini

https://backpack.tf/suggestion/5cd5ea8e67807257ae6dbfc3 - 25 Keys

Sale 6) Sold for an Australium Sniper Rifle (~23 Keys) + 2 Keys

https://backpack.tf/profiles/76561198132527164#!/compare/1556409600/1556496000

23 + 2 = 25 Keys

Sale 7) Bulk sale

https://backpack.tf/profiles/76561198244409420#!/compare/1556496000/1556582400

https://marketplace.tf/items/30120;5;u62 - Sold for $52.99 when Keys were ~$1.80 each

https://marketplace.tf/items/5021;6/Mann%20Co.%20Supply%20Crate%20Key

52.99 / 1.8 = 29.42, which rounds to 29 Keys

https://imgur.com/a/dF9nWpT - Buyers at 23 Keys

https://backpack.tf/u/76561198020382415

https://backpack.tf/u/76561198119634686