Item 1

https://backpack.tf/item/11007543792

Sale #1

Untraceable-

Seller: https://backpack.tf/profiles/76561198311498888#!/compare/1684627200/1684886400

Buyer :https://backpack.tf/profiles/76561198850121720#!/compare/1684972800/1685059200

Sale #2

Only 5 keys match IDs of the unusual and keys in buyer's side, incomplete and untraceable-

Seller: https://backpack.tf/profiles/76561198850121720#!/compare/1685491200/1685577600

Buyer: https://backpack.tf/profiles/76561198113655603#!/compare/1685577600/1685923200

Sale #3

Bulk sale-

Seller: https://backpack.tf/profiles/76561198113655603#!/compare/1686009600/1686182400

Buyer: https://backpack.tf/profiles/76561199219758482#!/compare/1686009600/1686096000

Marketplace.tf Sales

https://marketplace.tf/items/tf2/1162;5;u3087

MP.TF Sale #1

Sold for $39.99 on June 15, 2023

Key Price Average @ $1.98ish

39.99/1.98 = 20.19ish keys

MP.TF Sale #2

Sold for $39.99 on August 4, 2023

Key Price Average @ $1.95

39.99/1.95 = 20.50ish keys

MP.TF Sale #3

Sold for #39.99 on August 9, 2023

Key Price Average @ $1.99ish

39.99/1.99 = 20.09ish keys

Sales @ 20, 20, 21

Taking 20-21 here