Sale 1:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198065409820#!/compare/1531872000/1531958400

Buyer: https://backpack.tf/profiles/76561198367264041#!/compare/1531872000/1531958400

X = 10

Sale 2:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198385940902#!/compare/1532217600/1532304000

Buyer: https://backpack.tf/profiles/76561198306014701#!/compare/1532304000/1532390400

Bot.tf confirms: https://i.imgur.com/atkLEPV.png

X = 10

Sale 3:

Sold for 10 keys + 4 ref?

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1530144000/1530230400

https://backpack.tf/item/4697159988 - Buyer is untraceable.

Bot.tf confirms, but it is unreliable. https://i.imgur.com/atkLEPV.png

X = 10

Sale 4:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198180946791#!/compare/1526342400/1526601600

Buyer: https://backpack.tf/profiles/76561198085966081#!/compare/1526515200/1526601600

X = 10

Sale 5:

Sold for 9 keys + ~1 key in metal (ID’s match)

Seller: https://backpack.tf/profiles/76561197994697258#!/compare/1527379200/1527465600

Buyer: https://backpack.tf/profiles/76561198184685457#!/compare/1524528000/1527897600

X = 10

Sale 6:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198341086501#!/compare/1525737600/1525824000

Buyer: https://backpack.tf/profiles/76561198094060854#!/compare/1525737600/1525824000

X = 10

Sale 7:

Sold for 10 keys + 8 ref?

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1525996800/1526083200

https://backpack.tf/item/1278180971 - Buyer is untraceable.

Bot.tf confirms, but it is unreliable. https://i.imgur.com/atkLEPV.png

X = 10?

Sale 8:

Sold with ~2.5 keys in pure/items for Strange Pro. KS Machina (12)

http://www.tf2outpost.com/trade/29624663 - B/O of 11

Seller: https://backpack.tf/profiles/76561198026503248#!/compare/1525737600/1525824000

Buyer: https://backpack.tf/profiles/76561198341086501#!/compare/1525737600/1525824000

X = 9.5

Sale 9:

Sold for 9 keys + ~0.5 keys in robo parts

Seller: https://backpack.tf/profiles/76561198129797836#!/compare/1526601600/1526688000

Buyer: https://backpack.tf/profiles/76561198310495200#!/compare/1526515200/1526601600

X = 9.5

Sale 10:

Sold to a bot for 9 keys + 20 ref?

Seller: https://backpack.tf/profiles/76561198184685457#!/compare/1528502400/1528761600

Buyer: https://backpack.tf/profiles/76561198304138933#!/compare/1528675200/1528761600

Untraceable. Bot.tf confirms, but it is unreliable.

X = 9.5?

Sale 11:

Sold to a bot for 9 keys + 20 ref?

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1526083200/1526169600

Buyer: https://backpack.tf/profiles/76561198129386527#!/compare/1526083200/1526169600

Untraceable. Bot.tf confirms, but it is unreliable. https://i.imgur.com/atkLEPV.png

X = 9.5?

Sale 12:

Sold to a bot for 8 keys + 2 ref?

Seller: https://backpack.tf/profiles/76561198380114520#!/compare/1531958400/1532131200

Buyer: https://backpack.tf/profiles/76561198385940902#!/compare/1532044800/1532131200

Untraceable. Bot.tf confirms, but it is unreliable. https://i.imgur.com/atkLEPV.png

X = 8?

Sale 13:

Bulk for Pro. KS Aus Rocket Launcher

Seller: https://backpack.tf/profiles/76561198121555078#!/compare/1526774400/1526860800

Buyer: https://backpack.tf/profiles/76561197994697258#!/compare/1526774400/1526860800

Sale 14:

Bulk for Aus Knife

Seller: https://backpack.tf/profiles/76561198275154229#!/compare/1531180800/1531267200

Buyer: https://backpack.tf/profiles/76561198337583821#!/compare/1531180800/1531267200

Sale 15:

Bulk for Pro. KS Aus Knife and other things

Seller: https://backpack.tf/profiles/76561198337583821#!/compare/1531180800/1531267200

Buyer: https://backpack.tf/profiles/76561198065409820#!/compare/1531180800/1531267200

Sellers:

~10.3 keys:

https://i.imgur.com/FFafhha.png

https://backpack.tf/item/276433279

Sales at:

9.5 (2x)

10 (6x)

And untraceable sales at 8, 9.5 (2x) and 10.

Going with 9.5-10.

https://backpack.tf/profiles/76561198122057139#!/compare/1532908800/1532995200

https://backpack.tf/profiles/76561198301336678#!/compare/1532908800/1532995200

bulk for nuts brown bomber

https://backpack.tf/profiles/76561198301336678#!/compare/1532908800/1532995200

https://backpack.tf/profiles/76561198449333838#!/compare/1532822400/1532995200

untraceable, only the taunts in the 2nd link match.