Sale 1:

Sold for DBD Hard Counter (13)

No outpost

Seller: https://backpack.tf/profiles/76561198161322138#!/compare/1508716800/1509235200

Buyer: https://backpack.tf/profiles/76561198119428262#!/compare/1509148800/1509235200

X = 13

Sales 2 & 3:

Sold for $21.99 and $23.88 on Marketplace.tf

https://marketplace.tf/items/251;5;u34

21.99/1.98 = ~11.1

23.88/1.98 = ~12.1

X = 11 and 12

Sale 4:

Bulk for Aussie Flamethrower

Seller: https://backpack.tf/profiles/76561198310515197#!/compare/1507334400/1507852800

Buyer: https://backpack.tf/profiles/76561198351299890#!/compare/1507593600/1507680000

Sale 5:

Bulk for Green Energy Industrial Festivizer

Seller: https://backpack.tf/profiles/76561198119428262#!/compare/1509235200/1509408000

Buyer: https://backpack.tf/profiles/76561198218497692#!/compare/1509235200/1509408000

Sale 6:

Sold for Orbiting Fire Bloke’s Bucket Hat

http://www.tf2outpost.com/trade/29395710 - B/O of 10.5

Seller: https://backpack.tf/profiles/76561198359394527#!/compare/1507766400/1507852800

Buyer: https://backpack.tf/profiles/76561198122047881#!/compare/1507766400/1507852800

http://www.tf2outpost.com/trade/29390600 - Bloke’s seller had a B/O of 11. Can be used on the bloke.

Sellers:

11 keys:

http://www.tf2outpost.com/trade/29465351 - 5 days

Offers:

http://www.tf2outpost.com/trade/29469342

Sales at:

11

12

13

Going with 11-13.