Sale 1:

Sold for 11 keys + ~1 key in metal/items

Seller: https://backpack.tf/profiles/76561198292641211#!/compare/1548374400/1548460800

Buyer: https://backpack.tf/profiles/76561198432540484#!/compare/1548374400/1548460800

https://backpack.tf/item/2498767664

X = 12

Sale 2:

Sold for 6 keys + spelled item (6) + metal

Seller: https://backpack.tf/profiles/76561198432540484#!/compare/1548374400/1548460800

Buyer: https://backpack.tf/profiles/76561198226262240#!/compare/1548374400/1548460800

https://backpack.tf/item/2498767664

X = 12

Sale 3:

Sold for 12 keys

Seller: https://backpack.tf/profiles/76561198140316312#!/compare/1548633600/1548720000

Buyer: https://backpack.tf/profiles/76561198100765763#!/compare/1548633600/1548720000

https://backpack.tf/item/2498767664

X = 12

Sale 4:

Sold for 11 keys

Seller: https://backpack.tf/profiles/76561198327078449#!/compare/1546992000/1547078400

Buyer: https://backpack.tf/profiles/76561198144379747#!/compare/1546992000/1547078400

https://i.imgur.com/KgbsyaY.png - bot.tf confirms

X = 11

Sale 5:

Sold for 11 keys (Buyer’s end)

Seller: https://backpack.tf/profiles/76561198337734785#!/compare/1547078400/1547164800

Buyer: https://backpack.tf/profiles/76561198091502579#!/compare/1547078400/1547164800

https://backpack.tf/item/2249720446

X = 11

Sale 6:

Sold for 10 keys (Buyer’s end)

Seller: https://backpack.tf/profiles/76561198446606701#!/compare/1548547200/1548633600

Buyer: https://backpack.tf/profiles/76561198140316312#!/compare/1548547200/1548633600

https://backpack.tf/item/2498767664

X = 10

Sale 7:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198068362716#!/compare/1543708800/1543795200

Buyer: https://backpack.tf/profiles/76561198069414668#!/compare/1543708800/1543795200

https://backpack.tf/item/3902923956

X = 10

Sale 8:

Sold for 10 keys + cheap items

Seller: https://backpack.tf/profiles/76561198069414668#!/compare/1544659200/1544745600

Buyer: https://backpack.tf/profiles/76561198253797901#!/compare/1544659200/1544745600

https://backpack.tf/item/3902923956

X = 10

Sale 9:

Sold for 10 keys + 20 ref

Seller: https://backpack.tf/profiles/76561198337734785#!/compare/1546819200/1546905600

Buyer: https://backpack.tf/profiles/76561198150129955#!/compare/1546819200/1546905600

https://backpack.tf/item/3902923956

X = 10

Other Sales:

https://backpack.tf/item/3902923956 (#1-4)

https://backpack.tf/item/2498767664 (#5 & #6)

https://backpack.tf/item/2249720446 (#7 & #8)

https://backpack.tf/item/2089478268 - tradeit

#1

Bulk for Purple Confetti Sergeant’s Drill Hat + other items

https://backpack.tf/profiles/76561198205978243#!/compare/1543622400/1543708800

https://backpack.tf/profiles/76561198068362716#!/compare/1543708800/1543795200

#2

Untraceable

https://backpack.tf/profiles/76561198253797901#!/compare/1545177600/1545436800

https://backpack.tf/profiles/76561198062301628#!/compare/1544832000/1545523200

only 1 key and 3 ref match

#3

Untraceable-ish

https://backpack.tf/profiles/76561198062301628#!/compare/1545523200/1545696000

https://backpack.tf/profiles/76561198337734785#!/compare/1545609600/1545696000

Would’ve sold for 10 keys + some ref, I can guarantee, but we can’t see the last key here.

#4

Untraceable

https://backpack.tf/profiles/76561198150129955#!/compare/1546905600/1547164800

https://backpack.tf/profiles/76561198342776231#!/compare/1546646400/1547164800

#5

Sold with ~2 keys in items for Dead Presidents Tyrantium Helmet

https://backpack.tf/profiles/76561198071225282#!/compare/1548028800/1548115200

https://backpack.tf/profiles/76561198292641211#!/compare/1547856000/1548028800

Using on the Helmet.

#6

Bulk for Haunted Ghosts Cloud Crasher

https://backpack.tf/profiles/76561198100765763#!/compare/1548806400/1549152000

https://backpack.tf/profiles/76561198164651434#!/compare/1549065600/1549152000

#7

Untraceable, only 7 keys match on the buyer’s end

https://backpack.tf/profiles/76561198306756308#!/compare/1543017600/1543536000

https://backpack.tf/profiles/76561198327078449#!/compare/1543449600/1543536000

https://i.imgur.com/KgbsyaY.png - labelled as 9 keys + 24 ref

#8

Untraceable

https://backpack.tf/profiles/76561198144379747#!/compare/1547078400/1547164800

https://backpack.tf/profiles/76561198337734785#!/compare/1547078400/1547164800

#9

SCM

https://backpack.tf/profiles/76561198004610923#!/compare/1543276800/1543622400

https://backpack.tf/profiles/76561198271964253#!/compare/1542499200/1544659200

Sellers:

https://i.imgur.com/8EUzqks.png

https://backpack.tf/item/2498767664 - 12 keys

https://backpack.tf/item/2249720446 - 13 keys

Sales at:

10 (4x)

11 (2x)

12 (3x)

10 is far too common to be excluded. Additionally, unusable sales #3 & #7 would support 10 being in the range. Keeping 10.

Going with 10-12.