Sellers:

https://marketplace.tf/items/30810;5;u109

https://backpack.tf/item/5761519883

http://www.tf2outpost.com/trade/29202325 - b/o: $59.99 = 29 keys

http://www.tf2outpost.com/trade/29208012 - b/o: 24 keys (1 day)

http://www.tf2outpost.com/trade/28862826 - b/o: 40 keys (6 months)

http://www.tf2outpost.com/trade/29205257 - b/o: 23 keys (3 days)

http://www.tf2outpost.com/trade/28893806 - b/o: 25 keys (1 month)

Sold:

http://www.tf2outpost.com/trade/28866135

http://backpack.tf/profiles/76561198360188493#!/compare/1492387200/1492905600 - sold for Neutron Star Big Topper (26) = 26 keys (outlier)

http://www.tf2outpost.com/trade/29200105

http://backpack.tf/profiles/76561198048008254#!/compare/1493683200/1493769600 - ?

http://backpack.tf/profiles/76561198137799038#!/compare/1493510400/1493769600

http://backpack.tf/profiles/76561198048008254#!/compare/1493424000/1493510400 - ?

http://www.tf2outpost.com/trade/29200105

http://backpack.tf/profiles/76561198048008254#!/compare/1493424000/1493510400

http://backpack.tf/profiles/76561198048008254#!/compare/1493337600/1493424000 - ?

http://www.tf2outpost.com/trade/28705308

http://backpack.tf/profiles/76561198145642912#!/compare/1492819200/1493424000 - sold for Max's Severed Head (19) = 19 keys

http://backpack.tf/profiles/76561198111608504#!/compare/1491177600/1491264000

http://backpack.tf/profiles/76561198299364784#!/compare/1491004800/1491177600 - ?

http://www.tf2outpost.com/trade/28881143

http://backpack.tf/profiles/76561198338556449#!/compare/1492905600/1492992000 - sold with Voltaic Hat Protector A Head Full of Hot Air (14) for Miami Nights Hot Dogger (41) = 27 keys (outlier)

http://backpack.tf/profiles/76561198273681900#!/compare/1492214400/1492300800 - sold for Orbiting Fire Hottie's Hoodie (18) = 18 keys (low)

http://backpack.tf/profiles/76561198319849652#!/compare/1492214400/1492300800

http://backpack.tf/profiles/76561198319849652#!/compare/1491868800/1492214400 - ?

http://www.tf2outpost.com/trade/28876659

http://backpack.tf/profiles/76561198087172601#!/compare/1492128000/1492214400 - sold for Miami Nights Ye Olde Baker Boy (25) = 25 keys

http://backpack.tf/profiles/76561198053568814#!/compare/1492041600/1492128000 - bulk

http://backpack.tf/profiles/76561197996718388#!/compare/1490659200/1490745600 - sold for 19 keys

http://backpack.tf/profiles/76561197996718388#!/compare/1490572800/1490659200 - ?

http://backpack.tf/profiles/76561198114957534#!/compare/1490572800/1490659200 - ?

http://backpack.tf/profiles/76561198114957534#!/compare/1490400000/1490486400 - ?

http://backpack.tf/profiles/76561198252511772#!/compare/1490400000/1490486400 - sold for Strange Specialized Killstreak Australium Tomislav (14) + sweets (1) = 15 keys (low)

http://www.tf2outpost.com/trade/28863385

http://backpack.tf/profiles/76561198176960099#!/compare/1493337600/1496361600 - bulk

http://backpack.tf/profiles/76561198090938903#!/compare/1491264000/1491696000

http://backpack.tf/profiles/76561198037974036#!/compare/1489363200/1491609600 - ?

http://backpack.tf/profiles/76561198126112268#!/compare/1494115200/1494201600 - sold for Starstorm Insomnia Cranial Carcharodon (14) + Circling Peace Sign Ol' Geezer (13) = 27 keys (outlier)

http://backpack.tf/profiles/76561198321944467#!/compare/1492560000/1494201600 - sold with Strange Professional Killstreak Australium Blutsauger (8) for Cloud 9 Noble Amassment of Hats (27) = 19 keys

http://backpack.tf/profiles/76561198011321852#!/compare/1491523200/1491609600

http://backpack.tf/profiles/76561198051830811#!/compare/1490572800/1491696000 - ?

http://www.tf2outpost.com/trade/28906982

http://backpack.tf/profiles/76561198355387742#!/compare/1493683200/1493769600

http://backpack.tf/profiles/76561198090407838#!/compare/1493251200/1493769600 - sold for bunch of items (23) = 19 keys b/o

http://backpack.tf/profiles/76561198156379159#!/compare/1496102400/1496188800 - sold for Disco Beat Down Hottie's Hoodie (22) + 3 keys + metal (1) + sweets (1) = 27 keys (outlier)

http://backpack.tf/profiles/76561198076453268#!/compare/1494115200/1494460800 - ?

http://backpack.tf/profiles/76561198257628196#!/compare/1493942400/1494028800

http://backpack.tf/profiles/76561198076453268#!/compare/1493942400/1494028800 - ?

http://backpack.tf/profiles/76561198257628196#!/compare/1493769600/1493856000 - sold for Starstorm Slumber Nasty Norsemann (23) = 23 keys

http://backpack.tf/profiles/76561198071167440#!/compare/1493769600/1493856000 - sold for 19 keys + sweets (1) = 20 keys

http://backpack.tf/profiles/76561198101197482#!/compare/1493510400/1493596800 - sold with sweets (2) for Hot Specialized Killstreak Blitzkrieg Pistol (Field-Tested) (25) = 23 keys

http://backpack.tf/profiles/76561198265300713#!/compare/1492992000/1493078400

http://backpack.tf/profiles/76561198101197482#!/compare/1492905600/1493078400 - sold with sweets (1) for Strange Specialized Killstreak Australium Sniper Rifle (24) = 23 keys

http://www.tf2outpost.com/trade/28874675

http://backpack.tf/profiles/76561198263995096#!/compare/1492041600/1492128000 - sold for Miami Nights Halogen Head Lamp (15) + 5 keys = 20 keys

http://www.tf2outpost.com/trade/28866820

http://backpack.tf/profiles/76561198084668327#!/compare/1491696000/1491782400 - sold for Orbiting Fire Surgeon's Stahlhelm (18) = 18 keys (low)

http://backpack.tf/profiles/76561198050197875#!/compare/1491350400/1491609600 - sold for Tesla Coil Helmet Without a Home (20) + 1 key = 21 keys

http://backpack.tf/profiles/76561198111608504#!/compare/1491177600/1491264000 - sold for 20 keys

http://backpack.tf/profiles/76561198091704531#!/compare/1491091200/1491177600

http://backpack.tf/profiles/76561198111608504#!/compare/1491091200/1491177600 - sold for 5 keys + ?

http://backpack.tf/profiles/76561198344933095#!/compare/1490918400/1491004800 - sold for 21 keys

http://www.tf2outpost.com/trade/28806985

http://backpack.tf/profiles/76561197980218669#!/compare/1492041600/1492128000 - sold for Starstorm Insomnia Noble Nickel Amassment of Hats (25) + 2 keys + sweets (1) = 28 keys (outlier)

http://www.tf2outpost.com/trade/29178886

http://backpack.tf/profiles/76561198090956917#!/compare/1494633600/1494720000 - sold for 20 keys

http://backpack.tf/profiles/76561198321922965#!/compare/1494547200/1494892800 - sold with 13 keys + sweets (4) for Steaming Vive La France (34) = 17 keys (low)

http://backpack.tf/profiles/76561198115471878#!/compare/1493424000/1493510400 - sold for Circling Peace Sign Frenchman's Beret (18) + 3 keys + sweets (1) = 22 keys

http://backpack.tf/profiles/76561198157516238#!/compare/1491436800/1493510400 - bulk

http://backpack.tf/profiles/76561198041902665#!/compare/1490486400/1490572800

http://backpack.tf/profiles/76561198157516238#!/compare/1490486400/1490659200 - ?

http://backpack.tf/profiles/76561198217363140#!/compare/1490313600/1490486400 - sold with sweets (7) for Disco Beat Down Stainless Pot (27) = 20 keys

http://backpack.tf/profiles/76561198136852126#!/compare/1494201600/1494374400 - ?

http://backpack.tf/profiles/76561198180715845#!/compare/1490486400/1491264000 - ?

http://www.tf2outpost.com/trade/28850230

http://backpack.tf/profiles/76561198153807715#!/compare/1490918400/1491264000 - sold with 2 keys + sweets (2) for Blizzardy Storm Towering Pillar of Hats (25) = 21 keys

http://www.tf2outpost.com/trade/28849676

http://backpack.tf/profiles/76561198227911900#!/compare/1490572800/1490659200 - sold for Kill-a-Watt Airdog (14) = 14 keys (low)

http://backpack.tf/profiles/76561198165616199#!/compare/1494460800/1494633600

http://backpack.tf/profiles/76561198001714123#!/compare/1490054400/1495756800 - ?

http://backpack.tf/profiles/76561198165616199#!/compare/1491091200/1491955200 - scm

http://backpack.tf/profiles/76561198122575679#!/compare/1493510400/1493942400 - sold for Searing Plasma Buckaroos Hat (16) + 6 keys = 22 keys

http://backpack.tf/profiles/76561198015296784#!/compare/1492646400/1492732800 - sold for 19 keys

http://backpack.tf/profiles/76561198175442127#!/compare/1491868800/1492387200

http://backpack.tf/profiles/76561198015296784#!/compare/1491868800/1491955200 - ?

http://www.tf2outpost.com/trade/29200105

http://backpack.tf/profiles/76561198048008254#!/compare/1489968000/1490054400 - sold for 23 keys

http://backpack.tf/profiles/76561197961143295#!/compare/1492300800/1492387200

http://backpack.tf/profiles/76561198064682618#!/compare/1492387200/1492992000 - sold for 19 keys

http://backpack.tf/profiles/76561198261595073#!/compare/1492214400/1492300800

http://backpack.tf/profiles/76561197961143295#!/compare/1491955200/1492300800 - ?

http://www.tf2outpost.com/trade/28875308

http://backpack.tf/profiles/76561198133814282#!/compare/1492128000/1492214400 - sold for 12 keys (quicksold)

http://backpack.tf/profiles/76561198133814282#!/compare/1491955200/1492041600 - ?

http://backpack.tf/profiles/76561198048008254#!/compare/1495411200/1495497600

http://backpack.tf/profiles/76561198079315133#!/compare/1495324800/1495497600 - ?

http://backpack.tf/profiles/76561198048008254#!/compare/1494806400/1494892800 - ?

http://backpack.tf/profiles/76561198067729178#!/compare/1494028800/1494460800 - ?

http://backpack.tf/profiles/76561198208511783#!/compare/1493942400/1494201600

http://backpack.tf/profiles/76561198057768802#!/compare/1494028800/1494201600 - sold for Starstorm Insomnia Noble Nickel Amassment of Hats (25) = 25 keys

http://www.tf2outpost.com/trade/29200105

http://backpack.tf/profiles/76561198048008254#!/compare/1495756800/1495843200 - sold for 20 keys

http://backpack.tf/profiles/76561198181484562#!/compare/1495670400/1495843200

http://backpack.tf/profiles/76561198048008254#!/compare/1495584000/1495670400 - ?

http://backpack.tf/profiles/76561198072085386#!/compare/1495152000/1495929600

http://backpack.tf/profiles/76561198181484562#!/compare/1490400000/1495670400 - ?

Mini’s:

Miami Nights Halogen Head Lamp:

http://backpack.tf/suggestion/5931ccb70e2cad52cb6721f5 = 15 keys

Orbiting Fire Surgeon's Stahlhelm:

http://backpack.tf/suggestion/5931cee5e3387718e664f025 = 18 keys

Circling Peace Sign Frenchman's Beret:

http://backpack.tf/suggestion/5931dc3ce33877447b6f9bb6 = 18 keys

Conclusion:

sales at 12, 14, 15, 17, 18, 18, 19, 19, 19, 19, 19, 19, 20, 20, 20, 20, 20, 20, 21, 21, 21, 22, 22, 23, 23, 23, 23, 25, 25, 26, 27, 27, 27, 28

taking 19-25 keys