Item 1:

https://backpack.tf/item/7957322911

Sale 1:

Sold for 64 Keys

https://backpack.tf/item/4185041356 (Key ID: "15528309857")

https://imgur.com/R6cd8om — Former Nice Winter Crate Key 2012 was treated as a normal key in this case

https://backpack.tf/profiles/76561198859721638#!/compare/1741392000/1741478400

https://backpack.tf/profiles/76561198135234107#!/compare/1741478400/1743120000

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Item 2:

https://backpack.tf/item/7955736393

Sale 2:

Untraceable

https://backpack.tf/profiles/76561198104907923#!/compare/1742947200/1743206400

https://backpack.tf/profiles/76561199014888234#!/compare/1742688000/1743552000

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Item 3:

https://backpack.tf/item/7956652805

Sale 3:

Untraceable

https://backpack.tf/profiles/76561199026390261#!/compare/1738368000/1738454400

https://backpack.tf/profiles/76561198820875715#!/compare/1738454400/1738540800

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Item 4:

https://backpack.tf/item/2233527034

Sale 4:

https://marketplace.tf/items/tf2/146;5;u62

https://marketplace.tf/items/tf2/5021;6

$149.99/$1.90 = 79 Keys (Apr 19)

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Item 5:

https://backpack.tf/item/2793089426

Sale 5:

Untraceable

https://backpack.tf/profiles/76561198189826915#!/compare/1740355200/1744156800

https://backpack.tf/profiles/76561199765492456#!/compare/1740700800/1740787200

Sale 6:

Bulk

https://backpack.tf/profiles/76561198141187659#!/compare/1740700800/1740787200

https://backpack.tf/profiles/76561198311498888#!/compare/1740700800/1740787200

Sale 7:

Sold for ~60 Keys (Unusual ID: "15518363420")

https://backpack.tf/profiles/76561198311498888#!/compare/1741219200/1741305600

https://backpack.tf/profiles/76561199014888234#!/compare/1741219200/1741305600

Skipping gambling

Sale 8:

Dumped for ~45 Keys (Unusual ID: "15659338833")

https://backpack.tf/profiles/76561198343328308#!/compare/1744416000/1745280000

https://backpack.tf/profiles/76561199564942025#!/compare/1745107200/1745193600

Sale 9:

Sold for 60 Keys (Unusual ID: "15665305586")

https://backpack.tf/profiles/76561199564942025#!/compare/1745193600/1745280000

https://backpack.tf/profiles/76561199133022139#!/compare/1745193600/1745280000

//

Total Sales

45, 60, 60, 64, 79

https://imgur.com/2ywm9IB

Excluding 45 as low & 79 as a high outlier given that we have 3 sales @ ~60 keys

Taking 60 — 64 Keys

Unsolds:

https://backpack.tf/item/2139799885 — 85

https://backpack.tf/item/2793089426 — 88