Sellers:

http://www.tf2outpost.com/trade/29195295 - b/o: 27 keys (2 weeks)

Sold:

http://backpack.tf/profiles/76561198111772079#!/compare/1491609600/1491696000 - sold for Prof KS Australium Wrench (23) = 23 keys

Credits to Erik

https://backpack.tf/profiles/76561198033378852#!/compare/1493164800/1493251200

https://backpack.tf/profiles/76561198017911615#!/compare/1492646400/1493251200 - sold with 6 keys for Circling Heart Détective Noir (36) = 30 keys

http://backpack.tf/profiles/76561198151005351#!/compare/1492128000/1492300800 - sold for Molten Mallard Tungsten Toque = used to price that

http://backpack.tf/profiles/76561198138292052#!/compare/1492214400/1492819200 - bulk

http://backpack.tf/profiles/76561198003456281#!/compare/1494201600/1494288000 - sold with Orbiting Planets Buckaroos Hat + 1 key for Sunbeams Plug-In Prospector = better to update the plug in

http://backpack.tf/profiles/76561198344933095#!/compare/1491523200/1491609600

http://backpack.tf/profiles/76561198003456281#!/compare/1491436800/1491609600 - ?

http://backpack.tf/profiles/76561198042297359#!/compare/1490140800/1490227200 - bulk

http://backpack.tf/profiles/76561198114097422#!/compare/1492905600/1492992000 - sold for 30 keys

http://backpack.tf/profiles/76561197995194055#!/compare/1490486400/1490572800 - sold for 20 keys (quicksold)

http://backpack.tf/profiles/76561197996519748#!/compare/1490227200/1490313600 - bulk

http://backpack.tf/profiles/76561198253570951#!/compare/1495411200/1495497600 - involved with Green Energy Ye Oiled Baker Boy, used to price that

http://backpack.tf/profiles/76561198071737757#!/compare/1495324800/1495411200

http://backpack.tf/profiles/76561198253570951#!/compare/1495324800/1495411200 - sold with 2 keys + sweets (4) for Haunted Ghosts Engineer's Cap (35) = 29 keys

Mini's:

Haunted Ghosts Engineer's Cap:

http://imgur.com/a/Nb1WV - b/o: 35 keys

Conclusion:

sales at 20, 23, 29, 30, 30

taking 23-30 keys