Thank you PlantFoodClock and Bentry Suster for the corrections (surely this will be the last suggestion)

Sale 1

https://backpack.tf/item/1215235905

Sold for 300 keys

https://imgur.com/gallery/r-opef4WX

https://backpack.tf/profiles/76561198330661324#!/compare/1749340800/1749859200

https://backpack.tf/profiles/76561198247546180#!/compare/1749772800/1749859200

Sale 2

https://backpack.tf/item/556448200

Sold for $569.99 on Marketplace.tf on May 17, 2025

https://marketplace.tf/items/tf2/601;5;u38

Marketplace.tf valued keys at $1.95 on May 17

569.99 / 1.95 = ~292 keys

Sale 3

https://backpack.tf/item/556448200

Sold for 150 keys + Double spelled Strange Professional Killstreak Beggar's Bazooka (Also sold for 150 keys) = 300

https://backpack.tf/profiles/76561198057154811#!/compare/1748995200/1749600000

https://backpack.tf/profiles/76561198068640262#!/compare/1749600000/1749686400

https://backpack.tf/profiles/76561198220098345#!/compare/1749600000/1749686400 — Beggar's Bazooka trade (ID: 15826879105)

Sale 4

https://backpack.tf/item/559679347

Traded alongside 2 unusuals, untraceable

https://backpack.tf/profiles/76561198140803713#!/compare/1744502400/1744588800

https://backpack.tf/profiles/76561198145331385#!/compare/1744502400/1744588800