Sale 1:

Sold for ~16 keys in items

No outpost

Seller: http://backpack.tf/profiles/76561197960328421#!/compare/1467936000/1468022400

Buyer: http://backpack.tf/profiles/76561198074946606#!/compare/1467936000/1468022400

X = 16

Sale 2:

Sold for Orbiting Fire Ceremonial (11.5) + Strange Killstreak Festive Eyelander (2.5) + Spec. KS C.A.P.P.E.R (2.25)

http://www.tf2outpost.com/trade/28267592 - B/O of 15

Seller: http://backpack.tf/profiles/76561198068054713#!/compare/1466467200/1466553600

Buyer: http://backpack.tf/profiles/76561198137212552#!/compare/1466294400/1466467200

X = 15 (Capped by B/O)

Sale 3:

Sold for Terror-Watt Sober Stuntsman (15)

http://www.tf2outpost.com/trade/28299715 - B/O of 14.5

Seller: http://backpack.tf/profiles/76561198064511310#!/compare/1467244800/1467417600

Buyer: http://backpack.tf/profiles/76561198076875817#!/compare/1467331200/1467417600

Seller is currently re-selling the Stuntsman at 14 keys, capping at that

X = 14 (Capped by B/O)

Sale 4: (Dupe)

Sold for Strange Pro. KS Festive Stickybomb Launcher (9) + Strange Snack Attack (3.5) + Strange Spec. KS Loose Cannon (3)

http://www.tf2outpost.com/trade/28347530 - B/O of 14

Seller: http://backpack.tf/profiles/76561198137212552#!/compare/1469145600/1469232000

Buyer: http://backpack.tf/profiles/76561198147638191#!/compare/1469145600/1469232000

X = 14 (Capped by B/O)

Sale 5:

Quicksold for 13 keys

http://www.tf2outpost.com/trade/28314160 - No B/O

Seller: http://backpack.tf/profiles/76561198081963512#!/compare/1467763200/1467849600

Buyer: http://backpack.tf/profiles/76561198190503265#!/compare/1467763200/1467849600

X = 13

Sale 6: (Dupe)

Sold with 4 keys for Aussie Black Box (16) in about a day

http://www.tf2outpost.com/trade/28344942 - B/O of 14

Seller: http://backpack.tf/profiles/76561198134069816#!/compare/1468368000/1468800000

Buyer: http://backpack.tf/profiles/76561198137212552#!/compare/1468713600/1468800000

X = 12

Sale 7:

Sold for Aussie SMG (7.5) + 3 keys? + Spec. KS Quick Fix (<1)

No outpost

Seller: http://backpack.tf/profiles/76561198136954791#!/compare/1468627200/1468713600

Buyer: http://backpack.tf/profiles/76561198223981756#!/compare/1468627200/1468713600

Not too certain on the number of keys that were added, the buyer’s side shows 6 keys. It is possible that the keys moved too quickly to be scanned in the seller’s backpack

X = 11

Sale 8:

Sold for Peace Sign Madame Dixie

Seller: http://backpack.tf/profiles/76561198102685121#!/compare/1467072000/1467158400

Buyer: http://backpack.tf/profiles/76561198128005244#!/compare/1467072000/1467158400

Would prefer to not use it here and have it used to update the Madame Dixie instead

Sellers:

15 keys:

http://puu.sh/qfSRd/04765d54cf.png

http://backpack.tf/u/76561198069140011

Offers:

http://www.tf2outpost.com/trade/28316834

Sales at:

11

12

13

14 (2x)

15

16

Given the sales at 13 and 12 sold in about a day or less, anything below 14 can be considered an outlier

Going with 14-16