Shhhh... It's a secret.

Sale #1: 44 Keys

https://backpack.tf/profiles/76561198084126218#!/compare/1547683200/1547769600

Sale #2: Sold on mp.tf for $77.77

https://marketplace.tf/items/229;5;u46

Median Key Price on Jan. 11th: $1.75

77.77/1.75 = 44.44

Rounding down to 44 Keys.

Sale #3: Sold on mp.tf for $79.95

https://marketplace.tf/items/229;5;u46

Median Price of Keys on Jan. 19th: $1.79

79.95/1.79 = 44.66

Rounding up to 45 Keys.

Sale #4: Untraceable

https://backpack.tf/profiles/76561198155110999#!/compare/1547942400/1548028800

https://backpack.tf/profiles/76561198163645769#!/compare/1547942400/1548115200

Sale #5: Untraceable

https://backpack.tf/profiles/76561198080179568#!/compare/1547942400/1548028800

https://backpack.tf/profiles/76561198155110999#!/compare/1547942400/1548028800

Sale #6: Untraceable

https://backpack.tf/profiles/76561198080179568#!/compare/1547942400/1548028800

https://backpack.tf/profiles/76561198387446425#!/compare/1548979200/1554163200

Taking 44-45 Keys!

Feel free to report more sales or leave some feedback!

Thanks!