Sale 1:

https://backpack.tf/profiles/76561198085957674#!/compare/1527379200/1527465600

https://backpack.tf/profiles/76561198056531196#!/compare/1527292800/1527379200

Sold with Pro Ks Sniper(8) for Aussie Sniper(34)

Total is 26 keys.

Sale 2:

https://backpack.tf/profiles/76561198056531196#!/compare/1527811200/1527897600

https://backpack.tf/profiles/76561198174361109#!/compare/1527724800/1527811200

Sold on SCM

https://steamcommunity.com/market/pricehistory/?country=US&currency=1&appid=440&market_hash_name=Strange%20Unusual%20Cold%20Killer

Sold for 104.87 CAD

Keys at 3.22 CAD

Total is 32.57 keys

Sale 3:

https://backpack.tf/profiles/76561198174361109#!/compare/1528675200/1528761600

https://backpack.tf/profiles/76561198085957674#!/compare/1528675200/1528761600

Untrace.

Sale 4:

https://backpack.tf/profiles/76561198085957674#!/compare/1528761600/1528848000

https://backpack.tf/profiles/76561198002757046#!/compare/1528761600/1528848000

Untrace/QS

Sale 5:

https://backpack.tf/profiles/76561198002757046#!/compare/1529193600/1529280000

https://backpack.tf/profiles/76561198361129578#!/compare/1529193600/1529280000

Sold for 23 keys + 16 ref

Sale 6:

https://backpack.tf/profiles/76561198361129578#!/compare/1529280000/1529539200

https://backpack.tf/profiles/76561198388363768#!/compare/1529366400/1529452800

Sold for 15 keys + Aussie FaN(13)

Total is 28 keys

Sale 7:

https://backpack.tf/profiles/76561198388363768#!/compare/1530662400/1530748800

https://backpack.tf/profiles/76561198055622215#!/compare/1530576000/1530748800

Use there.

Sale 8:

https://backpack.tf/profiles/76561198055622215#!/compare/1531353600/1531440000

https://backpack.tf/profiles/76561198157631229#!/compare/1531353600/1531440000

Sold for D@D Bomber Bucket Hat

Bucket Hat Mini:

https://backpack.tf/suggestion/5b48e397cf6c75534c403fd4

Suggestion for 38.5 keys

Total sales @:

23.49, 26, 28, 32.57, 38.5 keys

https://i.imgur.com/O8UMHoH.jpg

Non-strange unsold for 35 for 4 months

Buyers for non strange up to 21 keys

Lets take 26 - 33 keys, calling 38.5 an outlier based on seller and 23.49 as it is closer to sellers than the next sale up.