Sale 1:

Sold for 15 keys + Jungle Wreath (~0.5)

http://www.tf2outpost.com/trade/29621207 - No B/O

Seller: https://backpack.tf/profiles/76561198043982289#!/compare/1523923200/1524009600

Buyer: https://backpack.tf/profiles/76561198096132005#!/compare/1523923200/1524009600

X = 16

Sale 2:

Sold for 15 keys

Seller: https://backpack.tf/profiles/76561198327078449#!/compare/1522195200/1522281600

Buyer: https://backpack.tf/profiles/76561198395872016#!/compare/1522195200/1522368000

Bot.tf confirms: https://i.imgur.com/lFPk5Vp.png

X = 15

Sale 3:

Sold for ’72 Shred Alert (Suggestion at 13.5) + ~4 keys in pure/items

http://www.tf2outpost.com/trade/29615596 - B/O of 14

Seller: https://backpack.tf/profiles/76561198196677807#!/compare/1523923200/1524096000

Buyer: https://backpack.tf/profiles/76561198070871290#!/compare/1523836800/1524096000

X = 14

Sale 4:

Sold for 13 keys in 1 day

Seller: https://backpack.tf/profiles/76561198271428863#!/compare/1524355200/1524441600

Buyer: https://backpack.tf/profiles/76561198190835542#!/compare/1524268800/1524528000

X = 13

Sale 5:

Sold in a day for 13 keys

Seller: https://backpack.tf/profiles/76561198166763414#!/compare/1524096000/1524182400

Buyer: https://backpack.tf/profiles/76561198182795337#!/compare/1524182400/1524268800

X = 13

Sale 6:

Sold for 12 keys

Seller: https://backpack.tf/profiles/76561198064428858#!/compare/1524268800/1524355200

Buyer: https://backpack.tf/profiles/76561198271428863#!/compare/1524268800/1524355200

X = 12

Sale 7:

Sold with items for 12 keys + 2 ref

Seller: https://backpack.tf/profiles/76561198139831684#!/compare/1523318400/1523404800

Buyer: https://backpack.tf/profiles/76561198302774496#!/compare/1523318400/1523404800

X = 12

Sale 8:

Sold with a key for Blizzardy Storm Old Guadalajara

Seller: https://backpack.tf/profiles/76561198096132005#!/compare/1524182400/1524268800

Buyer: https://backpack.tf/profiles/76561198064428858#!/compare/1524182400/1524268800

Can be used on the Guad.

Sale 9:

Sold with a couple keys in items for Steaming Pencil Pusher

Seller: https://backpack.tf/profiles/76561198395872016#!/compare/1523232000/1523577600

Buyer: https://backpack.tf/profiles/76561198139831684#!/compare/1523145600/1523232000

Should be used on the pencil

Sale 10:

Bulk for Smoking DCO

Seller: https://backpack.tf/profiles/76561198074178367#!/compare/1524700800/1524787200

Buyer: https://backpack.tf/profiles/76561198409674874#!/compare/1524614400/1524787200

’72 Shred Alert:

https://backpack.tf/suggestion/5b02f21544325a3aa977218e

Sellers:

14 keys:

http://www.tf2outpost.com/trade/29640756

Sales at:

12 (2x)

13 (2x)

14

15

16

Sales at 12 and 13 occurred quickly, but are too common to be excluded. Will exclude 12 and keep 13.

Going with 13-16.