Fire away.

https://backpack.tf/item/893988215

Sale 1) Sold for a Blizzardy Storm Stout Shako (16.5 Keys)

https://backpack.tf/profiles/76561198180724285#!/compare/1494892800/1494979200 - Buyer's Backpack

Rounds to 17 Keys

Sale 2) Sold for a Disco Beat Down Cyborg Stuntman + Strange Flame Thrower (2 Refined)

https://backpack.tf/profiles/76561198180724285#!/compare/1495756800/1495929600

Fits in the range with the current price or is low if I use the Seller at 12 Keys. There's also this Seller at 15 Keys: http://www.tf2outpost.com/trade/29278115

Sale 3) Sold for a Blizzardy Storm Furious Fukaamigasa (17 Keys) + 1 Reclaimed

https://backpack.tf/profiles/76561198011471692#!/compare/1495843200/1495929600

Rounds to 17 Keys

Sale 4) Sold for a Terror-Watt Tsarboosh (14.5 Keys) + 1 Key + ~0.9 Keys of Items

https://backpack.tf/profiles/76561198080501555#!/compare/1496620800/1496707200

14.5 + 1 + 0.9 = 16.4, which rounds to 16 Keys

Sale 5) Sold + ~6 Keys of Items for a Specialized Killstreak Australium Flame Thrower (~15 Keys)

https://backpack.tf/profiles/76561198267173308#!/compare/1497312000/1497484800 - Buyer's Backpack

Low Outlier.

Sale 6) Sold for 14 Keys + 4 Refined

https://backpack.tf/profiles/76561198267173308#!/compare/1499558400/1499817600

Rounds to 14 Keys

Sale 7) Sold + ~1.5 Keys of Items + 1 Key for an Australium Minigun (16 Keys)

https://backpack.tf/profiles/76561198016045615#!/compare/1500422400/1500768000 - Buyer's Backpack

16 - 1.5 - 1 = 13.5, which rounds to 14 Keys

Sale 8) Sold for 14 Keys

https://backpack.tf/profiles/76561198067315813#!/compare/1500595200/1500681600

Sale 9) Sold for 9 Keys

https://backpack.tf/profiles/76561198349780889#!/compare/1500681600/1500768000 - Buyer's Backpack

Low Outlier.

Sale 10) Quicksold for 13 Keys

https://backpack.tf/profiles/76561198065049657#!/compare/1500940800/1501027200

https://backpack.tf/item/1299947735

Sale 11) Sold for 15 Keys

https://backpack.tf/profiles/76561198108148076#!/compare/1495497600/1495584000

Sale 12) Quicksold for 13 Keys + 4 Refined

https://backpack.tf/profiles/76561198076059478#!/compare/1498608000/1498694400

https://backpack.tf/item/1530033298

Sale 13) Sold + Pool Party (3 Keys) for a Miami Nights Tough Guy's Toque

https://backpack.tf/profiles/76561198132246961#!/compare/1500854400/1500940800

Fits in the range. There's a Seller at 19 Keys: http://imgur.com/a/edfr3

Sale 14) Sold for 13 Keys

https://backpack.tf/profiles/76561198002757046#!/compare/1501113600/1501200000

Sale 15) Sold for a Starstorm Insomnia Wide-Brimmed Bandito (13 Keys) + ~6 Keys of Items

https://backpack.tf/profiles/76561198236990772#!/compare/1501113600/1501200000 - Buyer's Backpack

Regardless of if I take 13 for the Bandito or 12 from the current Sellers, this sale is a high Outlier.

Using the quicksales at 13 to rule that low, but they support 14. Using the higher sales to support 17.