Sale 1:

Sold with ~0.5 keys worth of painted junk for Infernal Flames Spent Well Spirits (18.5)

No outpost

Seller: http://backpack.tf/profiles/76561198105321885#!/compare/1494892800/1494979200

Buyer: http://backpack.tf/profiles/76561198036806580#!/compare/1494201600/1494979200

X = 18

Sale 2:

Sold for 16 keys

http://www.tf2outpost.com/trade/28376385 - B/O of 22

Seller: http://backpack.tf/profiles/76561198053172418#!/compare/1490659200/1491350400

Buyer: http://backpack.tf/profiles/76561198043853423#!/compare/1491350400/1491436800

X = 16

Sale 3:

sold for a couple crates

No outpost

Seller: http://backpack.tf/profiles/76561198153735609#!/compare/1492128000/1492214400

Buyer: http://backpack.tf/profiles/76561198051672963#!/compare/1492041600/1492646400

X = 0

Sellers:

17 keys:

http://i.imgur.com/PiavO2W.png - 10 months

http://backpack.tf/u/76561198006544512

http://www.tf2outpost.com/trade/29185629

Sales at:

0

16

18

18 is too high, with 17 going 10 months unsold. Excluding 18.

0 might be a little low, excluding 0.

Going with 16 flat.