Big Blub

https://backpack.tf/item/7829237768

Sale 1) SCM sale

https://backpack.tf/profiles/76561197995029705#!/compare/1560988800/1561075200

https://backpack.tf/profiles/76561198860975582#!/compare/1562112000/1562889600

https://backpack.tf/item/817421452

Sale 2) ?

https://backpack.tf/profiles/76561197968430374#!/compare/1559433600/1559520000

https://backpack.tf/profiles/76561198210225228#!/compare/1559433600/1559520000

Sale 3) SCM sale

https://backpack.tf/profiles/76561198210225228#!/compare/1559606400/1559692800

https://backpack.tf/profiles/76561198855228052#!/compare/1560902400/1561161600

https://backpack.tf/item/1690721250

Sale 4) ?

https://backpack.tf/profiles/76561198237294882#!/compare/1558915200/1563667200

https://backpack.tf/profiles/76561198121830870#!/compare/1558828800/1558915200

Sale 5) Sold for 11 Keys

https://backpack.tf/profiles/76561198121830870#!/compare/1559433600/1559520000

IDs match. Low outlier.

https://backpack.tf/item/1737263571

Sale 6) Sold for a Cloud 9 Bloke's Bucket Hat (13 Keys)

https://backpack.tf/profiles/76561198306875720#!/compare/1563321600/1563408000

Bloke's Mini

https://backpack.tf/profiles/76561198253536534#!/compare/1565481600/1565568000 - Sold for an Orbiting Fire Runner's Warm-Up + 1 Key

https://backpack.tf/profiles/76561198832602199#!/compare/1559952000/1560038400 - 14 Keys

https://backpack.tf/profiles/76561198394877897#!/compare/1563235200/1563321600 - 14 Keys

https://imgur.com/a/pyqZ1VK - Seller at 12 Keys

Sale 7) Sold for a Strange Circling TF Logo Climbing Commander

https://backpack.tf/profiles/76561198134602177#!/compare/1563494400/1563580800

https://backpack.tf/profiles/76561198866566566#!/compare/1563494400/1563580800

Using for the Climbing.

Sale 8) Bulk sale

https://backpack.tf/profiles/76561198866566566#!/compare/1563580800/1563667200

https://backpack.tf/profiles/76561198188754881#!/compare/1563580800/1563667200

Sale 9) Sold for 14 Keys

https://backpack.tf/profiles/76561198188754881#!/compare/1564617600/1564963200

https://backpack.tf/profiles/76561198104061772#!/compare/1564876800/1564963200

Sale 10) Bulk sale for an Anti-Freeze Killer Exclusive

https://backpack.tf/profiles/76561198104061772#!/compare/1565481600/1565568000

https://backpack.tf/item/1361848271

Sale 11) Bulk sale for a Galactic Gateway Hephaistos' Handcraft

https://backpack.tf/profiles/76561198362008411#!/compare/1558915200/1559001600

Sale 12) Sold for 11 Keys + 8 Refined

https://backpack.tf/profiles/76561198150163450#!/compare/1559520000/1559606400

Low outlier.

Sale 13) Sold for 14 Keys

https://backpack.tf/profiles/76561198337583821#!/compare/1559779200/1559952000

Sale 14) ?

https://backpack.tf/profiles/76561198145724270#!/compare/1562457600/1562630400

https://backpack.tf/profiles/76561198965533393#!/compare/1565481600/1565568000

https://marketplace.tf/items/tf2/135;5;u34 - Sold for $28 when Keys were ~$1.82 each

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

28 / 1.82 = 15.38, which rounds to 15 Keys

https://imgur.com/a/wmmoLco - 3 Day Seller at 14 Keys and a 17 Day Seller at 14 Keys. Buyer at 12 Keys

https://backpack.tf/item/1737263571

https://backpack.tf/item/7829237768

https://backpack.tf/u/76561198061836787

Calling 15 high and 11 low.