https://backpack.tf/item/8377833085

Untraceable:

https://backpack.tf/profiles/76561198042754411#!/compare/1605312000/1605398400

https://backpack.tf/profiles/76561198091502579#!/compare/1605398400/1605484800

Marketplace.tf seller at $60

https://backpack.tf/item/6912766279

35 keys:

https://backpack.tf/profiles/76561198850121720#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198091502579#!/compare/1600992000/1601078400

https://marketplace.tf/items/tf2/1172;5;u3033

https://backpack.tf/item/8341864183 September 22: $77.78/1.85=42.04 keys ~42

Two histories with other Marketplace.tf sales, not sure which one is which https://backpack.tf/item/7008084854 https://backpack.tf/item/6912766279

November 4: $64.99/1.82=35.71 keys ~36

November 6: $68/1.81=37.57 keys ~38

November 15: $48/1.78=26.97 keys ~27

December 6: $74.56/1.76=42.36 keys ~42

We have 27, 35, 36, 38, 42 and 42.

Excluding 27 because it's lower than buyers. Given the seller at 35 keys and the average of the values being 36.66 which is closer to 35-36 than 42, gonna exclude 42 too.

Going 35-36