Sale 1

https://backpack.tf/profiles/76561198152520083#!/compare/1545955200/1546041600

https://backpack.tf/profiles/76561198044684270#!/compare/1545868800/1545955200

Sold to buyorder and keys were used to buy the Bandito

Sale 2

https://backpack.tf/profiles/76561198147093437#!/compare/1542240000/1542326400

https://backpack.tf/profiles/76561198279227073#!/compare/1542240000/1542326400

Sold to a suspected scammer alt, excluding

Sale 3

https://backpack.tf/profiles/76561198826254247#!/compare/1542585600/1542672000

https://backpack.tf/profiles/76561198190514893#!/compare/1542412800/1542585600

Bulk for a Harvest Moon Command Elite

Sale 4

https://backpack.tf/profiles/76561198198103273#!/compare/1540166400/1540857600

https://backpack.tf/profiles/76561198099243560#!/compare/1540684800/1540857600

Sold from a Scammer

Sale 5

https://marketplace.tf/items/30977;5;u30

Sold on the 2nd December for 59.99$ (1.71)

= 35.08, rounding to 35 Keys.

Sales: 35

Buyorder sale was probably for 18. Since there are no other data points, going with 35 flat for now.

Buyorder for 18 keys from me was made after the suggestion.

That's it and that's all.