Sold:

https://backpack.tf/profiles/76561198118355049#!/compare/1494374400/1494460800 - sold for MN Vintage Merryweather (25) = 25 keys

Credits to Pen

https://backpack.tf/profiles/76561198062983803#!/compare/1495497600/1495756800 - sold for 27 keys

Credits to Pen

https://backpack.tf/profiles/76561198185057642#!/compare/1491782400/1491955200 - sold for Circling Peace Sign Toy Soldier (25) + sweets (4) = 29 keys

Credits to Pen

https://backpack.tf/profiles/76561198113302325#!/compare/1493596800/1494028800

https://webcache.googleusercontent.com/search?q=cache:N4UrgYkDJasJ:www.tf2outpost.com/trade/28904619 - sold for FoD Battin = 24 keys b/o

Credits to K1ng

https://backpack.tf/profiles/76561198119563409#!/compare/1494115200/1494201600 - sold for 26 keys

Credits to K1ng

https://backpack.tf/profiles/76561198113302325#!/compare/1494806400/1494892800 - sold for Miami Samur (24) + ~4 keys in sweets = 28 keys

Credits to K1ng

https://backpack.tf/profiles/76561198272153621#!/compare/1494892800/1494979200 - sold for HG Beanie (~30) = 30 keys

Credits to K1ng

https://backpack.tf/profiles/76561198081384929#!/compare/1498608000/1498694400 - sold for Kill-a-Watt Master's Yellow Belt (28) = 28 keys

http://www.tf2outpost.com/trade/29247291

https://backpack.tf/profiles/76561198338556449#!/compare/1498521600/1498694400 - sold for Burning Flames Football Helmet (29) = 29 keys

https://backpack.tf/profiles/76561198338556449#!/compare/1498348800/1498435200 - ?

http://www.tf2outpost.com/trade/29175833

https://backpack.tf/profiles/76561198174203179#!/compare/1498348800/1498435200 - sold for Miami Nights Flipped Trilby (22) = 22 keys

Conclusion:

sales at 22, 24, 25, 26, 27, 28, 28, 29, 29, 30

taking 24-30 keys