Sale 1:

Sold for $37.84 on Marketplace.tf

https://marketplace.tf/items/617;5;u36

https://backpack.tf/item/1697524863

37.84/2.03 = ~18.6

X = 19

Sale 2:

Sold for 15 keys + Mannrobics (1)

No outpost

Seller: https://backpack.tf/profiles/76561198167241030#!/compare/1501718400/1501804800

Buyer: https://backpack.tf/profiles/76561198301897810#!/compare/1501718400/1501804800

X = 16

Sale 3:

Sold for 16 keys

http://www.tf2outpost.com/trade/28805600 - B/O of 16

Seller: https://backpack.tf/profiles/76561198096760247#!/compare/1498176000/1498780800

Buyer: https://backpack.tf/profiles/76561198212085471#!/compare/1498694400/1498780800

X = 16

Sale 4:

Bulk for Green Energy Private Eye

Seller: https://backpack.tf/profiles/76561198182567266#!/compare/1499817600/1499990400

Buyer: https://backpack.tf/profiles/76561198216561389#!/compare/1499817600/1499990400

Sale 5:

Bulk for Blizzardy Dapper

Seller: https://backpack.tf/profiles/76561198063638461#!/compare/1498435200/1498521600

Buyer: https://backpack.tf/profiles/76561198179707937#!/compare/1498435200/1498521600

Sale 6:

Sold for Kill-a-Watt Lord Cockswain’s Pith Helm (17.5)

http://www.tf2outpost.com/trade/29251393 - B/O of > 17.5

Seller: https://backpack.tf/profiles/76561198212085471#!/compare/1498694400/1498780800

Buyer: https://backpack.tf/profiles/76561198182567266#!/compare/1498694400/1498780800

Pith has a 2-month-old seller at 17 keys. It’s nearly outdated, so this’d probably better suited on the Pith instead.

Sellers:

~16.5 keys:

http://i.imgur.com/uXS6RT4.png

http://i.imgur.com/DTmFosQ.jpg

17 keys:

http://i.imgur.com/rng3x3C.png - 2 weeks

18 keys:

http://i.imgur.com/oZKmM0L.png - 2 months

Sales at:

16 (2x)

19

19 is an outlier, especially with the 2-month-old seller at 18 keys. Excluding 18.

Going with 16 flat.