Sale 1:

Sold for 8 keys

Seller: https://backpack.tf/profiles/76561198448827930#!/compare/1561507200/1561593600

Buyer: https://backpack.tf/profiles/76561198200131337#!/compare/1561420800/1561680000

https://backpack.tf/item/6700010566

https://i.imgur.com/A8wF8cL.png - bot.tf confirms (the 7 key + 22 ref purchase came from a scammer)

X = 8

Sale 2:

Sold to a bot for 7 keys + half a key in metal

Seller: https://backpack.tf/profiles/76561198352738720#!/compare/1561334400/1561420800

Buyer: https://backpack.tf/profiles/76561198802465612#!/compare/1561334400/1561420800

https://backpack.tf/item/6466261069

https://i.imgur.com/A8wF8cL.png - bot.tf confirms

X = 7.5

Sale 3:

Sold for 15 ToD Tickets (~7 keys)

Seller: https://backpack.tf/profiles/76561198953145295#!/compare/1560470400/1560556800

Buyer: https://backpack.tf/profiles/76561198108048933#!/compare/1560470400/1560556800

https://backpack.tf/item/6570473396

X = 7

Marketplace Sales:

Sold for $15 & $10.29

https://marketplace.tf/items/tf2/1168;5;u3006

https://manic.tf/keyprice/?at=2019-06-27 - $15 / $1.84 = 8.15 keys

$10.29 is gonna be lower than classifieds buy orders.

X = 8

Other Sales:

https://backpack.tf/item/6700010566 (#1)

https://backpack.tf/item/6570473396 (#2)

https://backpack.tf/item/6570473396 (#3)

https://backpack.tf/item/6515281006 (#4)

https://backpack.tf/item/6497889359 (#5)

https://backpack.tf/item/7852394656 (#6)

https://backpack.tf/item/7525698362 - marketplace

https://backpack.tf/item/4962038840 - marketplace

https://backpack.tf/item/4958978178 - marketplace

https://backpack.tf/item/4952978579 - scrap

https://backpack.tf/item/4952910931 - tradeit/gambled

https://backpack.tf/item/6268030878 - scrap and tradeit

#1

Untraceable, missing a person in the history

https://backpack.tf/profiles/76561198169960987#!/compare/1560384000/1560470400

https://backpack.tf/profiles/76561198305279850#!/compare/1560470400/1560556800

#2

Untraceable

https://backpack.tf/profiles/76561198144136029#!/compare/1560470400/1560556800

https://backpack.tf/profiles/76561198953145295#!/compare/1560470400/1560556800

#3

Untraceable, only 5 keys and some metal match

https://backpack.tf/profiles/76561198108048933#!/compare/1560556800/1560643200

https://backpack.tf/profiles/76561198317903441#!/compare/1560470400/1560556800

#4

Untraceable

https://backpack.tf/profiles/76561198454615761#!/compare/1560988800/1561075200

https://backpack.tf/profiles/76561198113530727#!/compare/1560384000/1561075200

https://i.imgur.com/A8wF8cL.png - labelled as 8 keys + ~1 key in metal on bot.tf

Even if it were traceable, it would be higher than 3 current sellers, making this an outlier.

#5

Untraceable

https://backpack.tf/profiles/76561198072145089#!/compare/1559347200/1559433600

https://backpack.tf/profiles/76561198127061013#!/compare/1559433600/1559520000

#6

Sold with ~1 key in items for Orbiting Planets Tavish DeGroot

https://backpack.tf/profiles/76561198208677149#!/compare/1561852800/1561939200

https://backpack.tf/profiles/76561198136334765#!/compare/1561852800/1561939200

Gonna give priority to the pure sales we have here, and exclude this sale. Can be used on the DeGroot if necessary.

Sellers:

https://i.imgur.com/T6naIF6.png

https://backpack.tf/item/6911578836 - ~8.5 keys

https://backpack.tf/item/6570473396 - ~8.5 keys

https://backpack.tf/item/6466261069 - ~8.6 keys

https://backpack.tf/item/4958978178 - 9 keys

https://backpack.tf/item/5362785909 - 10 keys

Sales at:

7

7.5

8 (2x)

Going with 7-8.

7 keys

https://backpack.tf/profiles/76561198090866419#!/compare/1561939200/1562025600

https://backpack.tf/profiles/76561198097271466#!/compare/1561939200/1562025600

https://backpack.tf/item/7852394656