Sale 1:

Sold for Searing Bear (30) + 5 keys + less than half a key in metal

Seller: https://backpack.tf/profiles/76561198282471428#!/compare/1556582400/1556668800

Buyer: https://backpack.tf/profiles/76561198819564432#!/compare/1556582400/1556668800

https://backpack.tf/item/6969784915

X = 35

Sale 2:

Sold for 31 keys

Seller: https://backpack.tf/profiles/76561198305494036#!/compare/1557532800/1557619200

Buyer: https://backpack.tf/profiles/76561198053720151#!/compare/1557532800/1557619200

https://backpack.tf/item/6969784915

https://i.imgur.com/t752fXy.png - bot.tf confirms

X = 31

Sale 3:

Sold for 31 keys

Seller: https://backpack.tf/profiles/76561197994697258#!/compare/1556928000/1557014400

Buyer: https://backpack.tf/profiles/76561198107339012#!/compare/1556928000/1557014400

https://backpack.tf/item/5008529847

X = 31

Sale 4:

Sold for 29 keys + 15 ref

Seller: https://backpack.tf/profiles/76561198313362742#!/compare/1556496000/1556582400

Buyer: https://backpack.tf/profiles/76561198282471428#!/compare/1556496000/1556582400

https://backpack.tf/item/6969784915

X = 29

Sale 5:

Sold for 29 keys

Seller: https://backpack.tf/profiles/76561198048851745#!/compare/1559433600/1559520000

Buyer: https://backpack.tf/profiles/76561198056571743#!/compare/1559347200/1559520000

https://backpack.tf/item/4834401047

Seller’s compare shows 46, but 17 went towards the strange haunted ghosts blast defense.

X = 29

Sale 6:

Sold to a quickbuyer for 28 keys

Seller: https://backpack.tf/profiles/76561198027115020#!/compare/1558224000/1558310400

Buyer: https://backpack.tf/profiles/76561198337734785#!/compare/1558224000/1558310400

https://backpack.tf/item/6969784915

X = 28

Other Sales:

https://backpack.tf/item/6969784915 (#1-7)

https://backpack.tf/item/5008529847 (#8 & #9)

https://backpack.tf/item/4834401047 (#10)

#1

Bulk/untraceable

https://backpack.tf/profiles/76561198313362742#!/compare/1555459200/1555545600

https://backpack.tf/profiles/76561198086150918#!/compare/1555459200/1555545600

#2

Untraceable, only some keys match

https://backpack.tf/profiles/76561198819564432#!/compare/1556755200/1556841600

https://backpack.tf/profiles/76561198305494036#!/compare/1556755200/1556841600

https://i.imgur.com/t752fXy.png - labelled as ~28 keys

#3

Bulk for Miami Aztec Aggressor

https://backpack.tf/profiles/76561198056285342#!/compare/1558051200/1558137600

https://backpack.tf/profiles/76561198167286317#!/compare/1558051200/1558137600

#4

Something involving the Strange Unusual Flamethrower

https://backpack.tf/profiles/76561198167286317#!/compare/1558137600/1558224000

https://backpack.tf/profiles/76561198132113819#!/compare/1558137600/1558224000

#5

Untraceable

https://backpack.tf/profiles/76561198132113819#!/compare/1558224000/1558310400

https://backpack.tf/profiles/76561198027115020#!/compare/1558224000/1558310400

#6

Untraceable.

https://backpack.tf/profiles/76561198337734785#!/compare/1558396800/1558483200

https://backpack.tf/profiles/76561198154700747#!/compare/1558396800/1558483200

Only 27 keys match, I’m sure more were involved.

#7

Bulk for Lantern Anger

https://backpack.tf/profiles/76561198154700747#!/compare/1559260800/1559347200

https://backpack.tf/profiles/76561198114245825#!/compare/1559260800/1559347200

#8

Bulk for Green Energy DCO

https://backpack.tf/profiles/76561198056991995#!/compare/1554595200/1554854400

https://backpack.tf/profiles/76561197994697258#!/compare/1554768000/1554854400

#9

Untraceable

https://backpack.tf/profiles/76561198107339012#!/compare/1559606400/1559692800

https://backpack.tf/profiles/76561198131633162#!/compare/1559606400/1559692800

#10

Untraceable

https://backpack.tf/profiles/76561198056571743#!/compare/1559520000/1559606400

https://backpack.tf/profiles/76561198342161127#!/compare/1559520000/1559606400

Sellers:

https://i.imgur.com/7rXpKOV.png

https://backpack.tf/item/5621248780 - 40 keys

https://backpack.tf/item/4834401047 - 45 keys

Sales at:

28

29 (2x)

31 (2x)

35

https://i.imgur.com/IFJbnNm.png - Buyers at ~28-29 keys, but there are too many sales at around this price to just exclude them all. Given the single buyer at 29, and several sales at, or lower than 29 (some of them not even going to quickbuyers), I’ll exclude 28, but keep 29.

Going with 29-35.