Sellers:

http://www.tf2outpost.com/trade/29215947 - b/o: 17 keys (2 days)

http://www.tf2outpost.com/trade/29216283 - b/o: 16 keys (9 hours)

http://www.tf2outpost.com/trade/29216190 - b/o: 19 keys (2 days)

http://www.tf2outpost.com/trade/29212185

https://marketplace.tf/items/30479;5;u6

https://backpack.tf/item/3004481463 - b/o: $54 = 26 keys

Sold:

https://backpack.tf/profiles/76561198069420477#!/compare/1495411200/1495497600 - bulk

Credits to Pen

https://backpack.tf/profiles/76561198166102098#!/compare/1494720000/1494806400 - bulk

Credits to Pen

https://backpack.tf/profiles/76561198101767131#!/compare/1494288000/1494374400 - ?

Credits to Pen

https://backpack.tf/profiles/76561198167814659#!/compare/1492732800/1493164800 - sold for 17 keys

Credits to Pen

https://backpack.tf/profiles/76561198167814659#!/compare/1493164800/1494115200 - sold for Stormy Storm Hottie's (17) = 17 keys

Credits to Pen

https://backpack.tf/profiles/76561198105321885#!/compare/1495238400/1495411200 - sold with 4 keys for Flaming Lantern Gonzila (21) = used to price the gonzila

https://backpack.tf/profiles/76561198262288177#!/compare/1495238400/1495324800 - sold with 6 keys for an Orb. fire Napper's (25) = 19 keys (outlier)

Credits to Pen

https://backpack.tf/profiles/76561198015384426#!/compare/1494115200/1494201600 - sold with 2 keys for KaW Dragonborn (18) = 16 keys

Credits to Pen

Conclusion:

sales at 16, 17, 17, 19

sellers at 16, 17, 19, 26

taking 16-17 keys

Previous Suggestion: https://backpack.tf/suggestion/592b5c88c4404578177c48a9