Ol' Yeller

http://backpack.tf/item/4682640982

Sale 1) Sold for a Cauldron Bubbles Hotrod (23 Keys) + Eerie Orbiting Fire Berliner's Bucket Helm (18.5 Keys)

http://backpack.tf/profiles/76561198043337323#!/compare/1468627200/1468713600

23 + 18.5 = 31.5, which I'll round to 32 Keys

Hotrod Mini

http://backpack.tf/suggestion/57b6a52cc440453aa230d57a - 23 Keys

-----------------------------------------------------------------------------------------------------

http://backpack.tf/item/4939831371

Sale 2) Sold for a Blizzardy Storm Desert Marauder (18.5 Keys) + 14 Keys + ~7 Keys in Items

http://backpack.tf/profiles/76561198083783079#!/compare/1469491200/1469577600

18.5 + 14 + 7 = 39.5, which I'll round to 40 Keys

Desert Marauder Mini

http://backpack.tf/suggestion/57b6d659c44045548d420f12 - 18.5 Keys

Sale 3) Sold for a Professional Killstreak Australium Wrench (~27 Keys)

http://backpack.tf/profiles/76561198285120975#!/compare/1469664000/1469750400

-------------------------------------------------------------------------------------------------------------------------

http://backpack.tf/item/4550571327

Sale 4) Sold for 37 Keys

http://backpack.tf/profiles/76561197993826799#!/compare/1465516800/1465689600

--------------------------------------------------------------------------------------------------------------------------

http://backpack.tf/item/4576941457

Sale 5) Sold for ~38 Keys of Stuff

http://backpack.tf/profiles/76561198002757046#!/compare/1467244800/1467331200

-------------------------------------------------------------------------------------------------------------------------

http://backpack.tf/item/4295020737

Sale 6) Sold for a Cloudy Moon Buckaroos Hat

http://backpack.tf/profiles/76561197964171516#!/compare/1468627200/1468713600

Fits in the range.

---------------------------------------------------------

http://backpack.tf/item/4296734813

Sale 7) Sold for 40 Keys

http://backpack.tf/profiles/76561198094914459#!/compare/1467158400/1467676800 - Buyer's Backpack

------------------------------------------------------------------------------------------------------------------------------------------------------

Calling 27 an Outlier.