Sale 1:

https://backpack.tf/profiles/76561198193065651#!/compare/1550966400/1551484800

https://backpack.tf/profiles/76561198342161127#!/compare/1552694400/1552780800

QS

Sale 2:

https://backpack.tf/profiles/76561198157089186#!/compare/1550880000/1550966400

https://backpack.tf/profiles/76561198135492876#!/compare/1550880000/1550966400

Can trace ~2 keys...

Sale 3:

https://backpack.tf/profiles/76561198135492876#!/compare/1550880000/1550966400

https://backpack.tf/profiles/76561198379996789#!/compare/1550707200/1550966400

Sold for Bubbling Chieftain(11) + 1 key

Total is 12 keys

Sale 4:

https://backpack.tf/profiles/76561198379996789#!/compare/1552435200/1552521600

https://backpack.tf/profiles/76561198071588645#!/compare/1552435200/1552521600

Keys?

Sale 5:

https://backpack.tf/profiles/76561198071588645#!/compare/1552521600/1552608000

https://backpack.tf/profiles/76561198071230830#!/compare/1552435200/1552521600

Sold for ~11 keys in sweets

Sale 6:

https://backpack.tf/profiles/76561198071230830#!/compare/1552521600/1552608000

https://backpack.tf/profiles/76561198075492332#!/compare/1550620800/1552608000

Sold for 12 keys

Sale 7:

https://backpack.tf/profiles/76561198029514444#!/compare/1556323200/1556409600

https://backpack.tf/profiles/76561198053717045#!/compare/1556323200/1556409600

Bulk

Sale 8:

https://backpack.tf/profiles/76561198053717045#!/compare/1556496000/1556582400

https://backpack.tf/profiles/76561198042426740#!/compare/1556496000/1556582400

https://backpack.tf/profiles/76561198121842295#!/compare/1556496000/1556582400

Untrace / bulk

Sale 9:

https://backpack.tf/profiles/76561198121842295#!/compare/1556582400/1556668800

https://backpack.tf/profiles/76561198168425477#!/compare/1556409600/1556668800

Sold for CPS Sterling

Use there

Sale 10, 11:

https://marketplace.tf/items/721;5;u58

$33.33 / $1.79 = 18.62 keys

$22.77 / $1.8 = 12.65 keys <--- https://i.imgur.com/sWn6Cs7.jpg B/O of 12 keys

Total sales @:

11, 12, 12, 12, 18.62 keys

Taking 11 - 12 keys.