Sale 1:

https://backpack.tf/profiles/76561198112211859#!/compare/1525996800/1526169600

https://backpack.tf/profiles/76561198120768380#!/compare/1526169600/1526256000

Sold for 36 keys

Sale 2:

https://backpack.tf/profiles/76561198120768380#!/compare/1525910400/1526169600

https://backpack.tf/profiles/76561198188754881#!/compare/1525996800/1526169600

Sold for 39 keys

Sale 3:

https://backpack.tf/profiles/76561198188754881#!/compare/1526169600/1526342400

https://backpack.tf/profiles/76561198360831795#!/compare/1526083200/1526342400

Sold for Burning Gonzilla(48.5) + 4.38 keys in sweets.

http://www.tf2outpost.com/trade/29651719

B/O of 47 keys

Capping at 47 keys.

Total sales @:

36, 39, 47

Calling 47 an outlier.

Taking 36-39 keys.

Mindacos' part:

Eh, I think it'd be better to take a more conservative route here, and give this a wide range of 36-47. This abnorbally high duped sale on marketplace seems to support it too:

https://backpack.tf/item/2445078230

https://marketplace.tf/items/920;5;u12

36-47 should be better here.