You show the lights that stop me turn to stone. You shine them when I'm alone.

https://backpack.tf/item/282218953

Sale 1) Sold for a Stormy Storm Backwards Ballcap (21.5 Keys) + Midnight Whirlwind Deep Fried Desire (14.5 Keys) + 3 Keys

https://backpack.tf/profiles/76561198182268309#!/compare/1494460800/1495065600

http://www.tf2outpost.com/trade/29174288 - Had a Buyout of 40 Keys

21.5 + 14.5 + 3 = 39 Keys

Sale 2) Sold + 11 Keys + ~1 Key of Items for a Duped Purple Energy Flipped Trilby

https://backpack.tf/profiles/76561197993989727#!/compare/1495756800/1495843200

Low Outlier.

Sale 3) Sold for 21 Keys + Green Confetti Towering Pillar of Hats (20 Keys)

https://backpack.tf/profiles/76561197993989727#!/compare/1497830400/1497916800

http://www.tf2outpost.com/trade/29236190 - Capped by the Buyout of 37 Keys

https://backpack.tf/item/4978267481

Sale 4) Sold for a Purple Confetti Frickin' Sweet Ninja Hood (41 Keys)

https://backpack.tf/profiles/76561198038866814#!/compare/1495411200/1495670400

http://www.tf2outpost.com/trade/29183083 - Capped by the Buyout of 37 Keys

Sale 5) Sold for a Miami Nights Executioner (32.5 Keys) + 6 Keys + 2 Keys of Items

https://backpack.tf/profiles/76561198153806405#!/compare/1495670400/1495756800

32.5 + 6 + 2 = 40.5, which rounds to 41 Keys

Sale 6) Sold for a Haunted Ghosts Scotsman's Stove Pipe + ~3 Keys of Items + 2 Keys

https://backpack.tf/profiles/76561198000841936#!/compare/1495756800/1495843200

This would be better used for the Stove Pipe because it is 2 Years Outdated.

Sale 7) Sold for a Miami Nights Voodoo Juju + Bubbling Stainless Pot

https://backpack.tf/profiles/76561198255575294#!/compare/1495756800/1495843200

Low Outlier.

Sale 8) Sold + Blizzardy Storm Geisha Boy (15 Keys) for a Frostbite Brim Full of Bullets (40 Keys) + ~3 Keys of Items

https://backpack.tf/profiles/76561198239598834#!/compare/1499731200/1499817600 - Buyer's Backpack

Low Outlier. If I use the Brim's current price of 52.5 Keys, the sale falls in the range.

Geisha Mini

https://backpack.tf/profiles/76561198056095654#!/compare/1498867200/1498953600 - Sold + 8 Keys for a Vivid Plasma Big Elfin Deal (25 Keys)

http://www.tf2outpost.com/trade/29252930 - Capped by the Buyout of 15 Keys

Brim Mini

https://backpack.tf/profiles/76561198148511293#!/compare/1496966400/1497052800 - Sold + 30 Keys for a Secret Private Eye (70 Keys)

70 - 30 = 40 Keys

Private Micro

https://backpack.tf/profiles/76561197964171516#!/compare/1497484800/1497571200 - Sold for a Scorching Detective Noir (72.5 Keys) + 2 Keys

http://webcache.googleusercontent.com/search?q=cache:f2C1iSG6ZZcJ:www.tf2outpost.com/trade/29191398+&cd=1&hl=en&ct=clnk&gl=us - Capped by the Buyout of 70 Keys

Sale 9) Sold + Blizzardy Storm Geisha Boy (15 Keys, mini above) for a Tesla Coil Deep Cover Operator (56 Keys)

https://backpack.tf/profiles/76561198239598834#!/compare/1499817600/1499990400

56 - 15 = 41 Keys

Sale 10) Sold for a Miami Nights Bonk Boy (49.5 Keys)

https://backpack.tf/profiles/76561198192602363#!/compare/1499990400/1500076800

High Outlier

Sale 11) Sold for a Circling Hearts Noble (30.5 Keys)

https://backpack.tf/profiles/76561198202554772#!/compare/1499472000/1500076800

It's basically a free upgrade. Excluding.

https://backpack.tf/item/5375536433

Sale 12) Sold for 25 Keys

https://backpack.tf/profiles/76561198150613286#!/compare/1498694400/1499040000

Countered by Classified Buyers.

Sale 13) Sold for 28 Keys

https://backpack.tf/profiles/76561198080969972#!/compare/1499040000/1499126400

Countered by Classified Buyers.

Sale 14) Sold for 31 Keys

https://backpack.tf/profiles/76561198002757046#!/compare/1499472000/1499558400

Sale 15) Quicksold for 29 Keys

https://backpack.tf/profiles/76561198150928662#!/compare/1499817600/1499904000

Sale 16) Sold + ~2 Keys of Items for an Atomic Universal Translator (27 Keys) + Massed Flies Hound Dog (13 Keys)

https://backpack.tf/profiles/76561198175496874#!/compare/1500076800/1500163200

27 + 13 = 40 - 2 = 38 Keys

Using the multiple low/quick sales to justify 31 Keys being in the range.