Using last 2 months.

Sale 1:

Sold for 5 keys

https://backpack.tf/profiles/76561199043177646#!/compare/1703635200/1703721600

https://backpack.tf/profiles/76561198194542557#!/compare/1696118400/1703721600

https://backpack.tf/item/2709824770

= 5 keys

Sale 2:

Sold for 4 keys + 10.33 ref

https://backpack.tf/profiles/76561198453530349#!/compare/1701216000/1701302400 - Near ID: 13851107096 (keys only)

https://backpack.tf/profiles/76561198038963425#!/compare/1701216000/1701302400 - metal here matches

https://backpack.tf/item/2908474416

= 4.15 keys

Other Sales:

#1

https://backpack.tf/profiles/76561199391237428#!/compare/1701475200/1701561600

https://backpack.tf/profiles/76561199111073161#!/compare/1701475200/1701561600

https://backpack.tf/item/11944773691

Untraceable

#2

https://backpack.tf/profiles/76561199111073161#!/compare/1702512000/1702598400

https://backpack.tf/profiles/76561198178445551#!/compare/1702166400/1702598400

https://backpack.tf/item/11944773691

Untraceable, 2 keys match on seller's end.

#3

https://backpack.tf/profiles/76561198178445551#!/compare/1702166400/1702598400

https://backpack.tf/profiles/76561199026390261#!/compare/1702512000/1702598400

https://backpack.tf/item/11944773691

Untraceable, 1 key + 1 reclaimed matches.

#4

https://backpack.tf/profiles/76561199026390261#!/compare/1702684800/1702771200

https://backpack.tf/profiles/76561198089387766#!/compare/1702598400/1702771200

https://backpack.tf/item/11944773691

Sold for Fountain of Delight Luxury Lounge?

Not too sure this was a 1:1 deal, usually with trades to bot services like this, they'll value the items at an overly specific amount, and either request adds or compensate with metal. If it is correct, it should most likely fit in the range. It can also be used on the Luxury Lounge anyways, I'm gonna give precedent to pure sales here.

#5

https://backpack.tf/profiles/76561198392349684#!/compare/1702598400/1704758400

https://backpack.tf/profiles/76561198059601444#!/compare/1704067200/1704240000

https://backpack.tf/item/6667103931

Untraceable

#6

https://backpack.tf/profiles/76561198199729741#!/compare/1700524800/1700611200

https://backpack.tf/profiles/76561199161916038#!/compare/1700438400/1700524800

https://backpack.tf/item/3788382852

Untraceable, probably gambled. The rest of this item's history appears to have been gambled.

#7

https://backpack.tf/profiles/76561198154577774#!/compare/1700092800/1704758400

https://backpack.tf/profiles/76561199026390261#!/compare/1700006400/1700092800

https://backpack.tf/item/2908474416

Untraceable

#8

https://backpack.tf/profiles/76561199026390261#!/compare/1700697600/1700784000

https://backpack.tf/profiles/76561198271834729#!/compare/1700438400/1700870400

https://backpack.tf/item/2908474416

Untraceable. Some metal matches on the seller's end, a key matches on the buyer's end.

#9

https://backpack.tf/profiles/76561198271834729#!/compare/1700870400/1703808000

https://backpack.tf/profiles/76561198453530349#!/compare/1700784000/1700870400

https://backpack.tf/item/2908474416

Untraceable

#10

https://backpack.tf/profiles/76561198278021848#!/compare/1702944000/1704758400

https://backpack.tf/profiles/76561198093230303#!/compare/1703116800/1703376000

https://backpack.tf/item/2761875033

SCM

#11

https://backpack.tf/profiles/76561198075965051#!/compare/1704153600/1704240000

https://backpack.tf/profiles/76561199135952616#!/compare/1704067200/1704153600

https://backpack.tf/item/5570671700

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20Oblooterated&at=2024-01-04T01:57:32.723Z - labelled as 3 keys + 3.33 ref

Untraceable

https://backpack.tf/item/12165387999 - mannco

https://backpack.tf/item/2699185782 - wasn't unusual at the time

Sellers:

https://imgur.com/a/Wrmp83P

https://backpack.tf/item/12165387999 - 10 keys

https://backpack.tf/item/5347143537 - 10 keys

Sales at:

4.15

5

Taking 4.15-5 keys.