Spooooooky

https://backpack.tf/item/3129094706

Sale 1) Sold for a Eerie Orbiting Fire Defiant Spartan + 6 Keys

https://backpack.tf/profiles/76561197993057065#!/compare/1501977600/1502064000

http://www.tf2outpost.com/trade/29314052 - Capped by the Buyout of 30 Keys

Sale 2) Sold for a Starstorm Slumber Hot Dogger (23 Keys) + Strange Nuts and Bolts L'Inspecteur (10 Keys) + ~8 Keys of Items

https://backpack.tf/profiles/76561198066701092#!/compare/1502150400/1502582400

23 + 10 + 8 = 41, which I'll round to 40 Keys

The Keys' histories don't match. I asked the Seller for confirmation.

L'Inspecteur Mini

https://marketplace.tf/items/622;5;u31;strange - Sold for $19.99, which was roughly 10 Keys at the time.

Sale 3) Quicksold for 28 Keys

https://backpack.tf/profiles/76561198002757046#!/compare/1503360000/1503446400