Sale 1:

Sold for 9 keys

No outpost

Seller: https://backpack.tf/profiles/76561198004517334#!/compare/1502928000/1503014400

Buyer: https://backpack.tf/profiles/76561198242652694#!/compare/1501632000/1503014400

X = 9

Sale 2:

Sold for 8 keys + 17 ref (> 0.5)

No outpost

Seller: https://backpack.tf/profiles/76561198054758757#!/compare/1502409600/1502496000

Buyer: https://backpack.tf/profiles/76561198291575048#!/compare/1501804800/1502409600

X = 9

Sale 3:

Bulk for Kill-a-Watt Front Runner

Seller: https://backpack.tf/profiles/76561198143957088#!/compare/1501632000/1501891200

Buyer: https://backpack.tf/profiles/76561198004517334#!/compare/1501459200/1501632000

Sale 4:

Sold with 2 keys for Steaming Counterfeit Billycock

Seller: https://backpack.tf/profiles/76561198027024671#!/compare/1503446400/1503792000

Buyer: https://backpack.tf/profiles/76561198067323951#!/compare/1503532800/1503792000

Should be used on the Billycock.

Sellers:

9 keys:

https://i.imgur.com/VCl8fRE.jpg - 2 months

10 keys:

https://i.imgur.com/rKCjZpw.png - 19 days

https://i.imgur.com/k3w0yX8.jpg - 21 days

Sales at:

9 (2x)

Going with 9 flat.