Sale 1:

Sold for $34.5 on Marketplace.tf

https://marketplace.tf/items/30093;5;u62

https://backpack.tf/item/2437833422

34.5/1.96 = ~17.6

X = 18

Sale 2:

Sold for Planets Airdog (Suggestion at 13) + 4 keys

No outpost

Seller: https://backpack.tf/profiles/76561198204018315#!/compare/1510531200/1510617600

Buyer: https://backpack.tf/profiles/76561198098096360#!/compare/1510531200/1510617600

X = 17

Sale 3:

Sold for 15 keys + 17 ref

http://www.tf2outpost.com/trade/29424327 - B/O of 16

Seller: https://backpack.tf/profiles/76561198108167626#!/compare/1510444800/1510531200

Buyer: https://backpack.tf/profiles/76561198105471167#!/compare/1510358400/1510531200

X = 16

Sale 4:

Sold for 15 keys + 30 ref in less than a day

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1510876800/1510963200

Buyer: https://backpack.tf/profiles/76561198092075869#!/compare/1510876800/1510963200

X = 16

Sale 5:

Sold for 15 keys + 30 ref

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1511481600/1511568000

Buyer: https://backpack.tf/profiles/76561198149556996#!/compare/1511481600/1511568000

Keys are on the Buyer’s end, ref is on the seller’s end. (6381651045 – near ID for the ref)

X = 16

Sale 6:

Sold with Robo Key for Spec. KS Aussie Knife (16)

http://webcache.googleusercontent.com/search?q=cache:iBP0-l7EqhsJ:www.tf2outpost.com/trade/29375563+&cd=1&hl=en&ct=clnk&gl=au – B/O of 16

Seller: https://backpack.tf/profiles/76561198064423172#!/compare/1506384000/1506470400

Buyer: https://backpack.tf/profiles/76561198381438914#!/compare/1506384000/1506470400

X = 15

Sale 7:

Quicksold for 15 keys + 6 ref

Seller: https://backpack.tf/profiles/76561198131633162#!/compare/1505865600/1505952000

Buyer: https://backpack.tf/profiles/76561198114545227#!/compare/1505865600/1505952000

X = 15

Sale 8:

Sold for 14 keys

http://www.tf2outpost.com/trade/29381638 - B/O of 15

http://webcache.googleusercontent.com/search?q=cache:b2uOsJSAoqAJ:www.tf2outpost.com/trade/29381638+&cd=1&hl=en&ct=clnk&gl=au – B/O was 18 during mid-October

Seller: https://backpack.tf/profiles/76561198073435210#!/compare/1509667200/1509753600

Buyer: https://backpack.tf/profiles/76561198108167626#!/compare/1509667200/1509753600

X = 14

Sale 9:

Sold for 15 keys + some amount of ref

Seller: https://backpack.tf/profiles/76561198304138933#!/compare/1510012800/1510099200

Buyer: https://backpack.tf/profiles/76561198255158705#!/compare/1509926400/1510099200

Compare link shows 15 ref was added, but I’m almost certain it was more than that. Don’t want to use this sale without knowing for sure that this sale is correct.

Sale 10:

Sold for Abduction Head Full of Hot Air

No outpost

Seller: https://backpack.tf/profiles/76561198150304602#!/compare/1506988800/1507593600

Buyer: https://backpack.tf/profiles/76561198385727483#!/compare/1507507200/1507593600

Can be used on the Head.

Sale 11:

Bulk for Green Energy Rack + Purple Energy Stash

Seller: https://backpack.tf/profiles/76561198114545227#!/compare/1509321600/1509408000

Buyer: https://backpack.tf/profiles/76561197995194055#!/compare/1509321600/1509408000

Sale 12:

Bulk for Vivid Fro

Seller: https://backpack.tf/profiles/76561198329446843#!/compare/1506470400/1506643200

Buyer: https://backpack.tf/profiles/76561198073435210#!/compare/1505692800/1506470400

Planets Airdog:

https://backpack.tf/suggestion/5a1d6acdcf6c7561786ebbc5

Sellers:

~15.9 keys:

https://i.imgur.com/IEQLBFK.png - 3 days

17 keys:

https://i.imgur.com/MSPq6DZ.jpg - 1 month

Sales at:

14

15 (2x)

16 (3x)

17

18

14 seems pretty low with 15 quickselling. That being said, sales below 16 are pretty common, so excluding sales below 16 isn’t too good of an idea. Excluding 14, keeping 15.

18 looks like an outlier, with the month-old seller at 17. Excluding 18.

Going with 15-17.