Using last 3 months, due to the lack of sales in the last 2 months.

Sale 1:

Sold for 3 keys + 28.55 ref (~0.45 keys)

https://backpack.tf/profiles/76561199026494523#!/compare/1702252800/1702339200

https://backpack.tf/profiles/76561198453530349#!/compare/1702252800/1702339200

https://backpack.tf/item/6819060720

= 3.45 keys

Sale 2: (+2 months)

Sold for 3 keys + 17.33 ref (~0.25 keys)

https://backpack.tf/profiles/76561198453530349#!/compare/1699401600/1699488000

https://backpack.tf/profiles/76561198161374911#!/compare/1699488000/1699574400

https://backpack.tf/item/6505304093

= 3.25 keys

Sale 3: (+2 months)

Sold for 3 keys + negligible metal

https://backpack.tf/profiles/76561199026390261#!/compare/1697500800/1697587200

https://backpack.tf/profiles/76561198069206704#!/compare/1697500800/1697673600

https://backpack.tf/item/12698489210

= 3 keys

Sale 4: (+2 months)

Sold with 13 ref (~0.2 keys) for 3 keys

https://backpack.tf/profiles/76561198453530349#!/compare/1700006400/1700092800

https://backpack.tf/profiles/76561198085795006#!/compare/1700006400/1700092800

https://backpack.tf/item/11767637025

= 2.8 keys

Sale 5:

Sold to a bot for 2 keys + 12 ref (~0.2 keys)

https://backpack.tf/profiles/76561198378840919#!/compare/1700265600/1700611200

https://backpack.tf/profiles/76561199072654974#!/compare/1700524800/1700611200

https://backpack.tf/item/6776681307

= 2.2 keys

Other Sales:

#1

https://backpack.tf/profiles/76561199111292616#!/compare/1703030400/1703116800

https://backpack.tf/profiles/76561199183171982#!/compare/1702944000/1703030400

https://backpack.tf/item/9587353706

Probably a backpack buy

#2

https://backpack.tf/profiles/76561198213970696#!/compare/1702857600/1705449600

https://backpack.tf/profiles/76561198890990852#!/compare/1702771200/1702857600

https://backpack.tf/item/8911713761

Untraceable

#3

https://backpack.tf/profiles/76561198135656220#!/compare/1701475200/1701648000

https://backpack.tf/profiles/76561199059698603#!/compare/1701561600/1701648000

https://backpack.tf/item/6262867486

Sold with about a key in items for Boundless Blizzard Jumping Jack. Hoping to use on that.

#4

https://backpack.tf/profiles/76561199059698603#!/compare/1704585600/1704672000

https://backpack.tf/profiles/76561198208327832#!/compare/1704326400/1704672000

https://backpack.tf/item/6262867486

Untraceable

#5 (+2 months)

https://backpack.tf/profiles/76561198870445180#!/compare/1698105600/1705449600

https://backpack.tf/profiles/76561198135388328#!/compare/1699833600/1699920000

https://backpack.tf/item/11767637025

Untraceable

#6 (+2 months)

https://backpack.tf/profiles/76561198135388328#!/compare/1699833600/1699920000

https://backpack.tf/profiles/76561198453530349#!/compare/1699833600/1699920000

https://backpack.tf/item/11767637025

Untraceable

#7 (+2 months)

https://backpack.tf/profiles/76561198355038741#!/compare/1698451200/1698624000

https://backpack.tf/profiles/76561198453530349#!/compare/1698537600/1698624000

https://backpack.tf/item/6505304093

Untraceable

#8 (+2 months)

https://backpack.tf/profiles/76561199061291714#!/compare/1698192000/1698278400

https://backpack.tf/profiles/76561199099521803#!/compare/1698192000/1698278400

https://backpack.tf/item/6252740962

Untraceable

#9

https://backpack.tf/profiles/76561198453530349#!/compare/1702857600/1702944000

https://backpack.tf/profiles/76561199110681797#!/compare/1702857600/1702944000

https://backpack.tf/item/6819060720

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20The%20Jumping%20Jack&at=2023-12-20T02:24:23.096Z - labelled as 2 keys

Untraceable, missing info in history.

#10

https://backpack.tf/profiles/76561199072654974#!/compare/1702857600/1702944000

https://backpack.tf/profiles/76561199110681797#!/compare/1702857600/1702944000

https://backpack.tf/item/6776681307

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20The%20Jumping%20Jack&at=2023-12-20T02:24:23.096Z - labelled as 2 keys

Same deal as #9.

https://backpack.tf/item/12397684067 - unusualified

https://backpack.tf/item/9850680232 - mannco/bot transfer

https://backpack.tf/item/6252740962 - mannco

https://backpack.tf/item/13173161119 - mannco

https://backpack.tf/item/7245042465 - mannco

https://backpack.tf/item/6273089474 - mannco

https://backpack.tf/item/6252784447 - unusualified

https://backpack.tf/item/6252780902 - mannco/bot transfer

Marketplace Sales:

https://marketplace.tf/items/tf2/30845;5;u3003

$9, November 17th

https://marketplace.tf/items/tf2/5021;6

Keys were $1.72 on November 17th

Unconfirmed Gladiator sales:

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20The%20Jumping%20Jack&at=2023-12-20T02:24:23.096Z - December 20th

2 keys (2x), seen in #9 and #10

https://gladiator.tf/sales?item=Holy%20Grail%20Taunt:%20The%20Jumping%20Jack&at=2023-12-16T02:28:33.187Z - December 16th

3 keys + 27.44 ref

Sellers:

https://imgur.com/a/MtAS8PK

https://backpack.tf/item/8911713761 - 3.75 keys

https://backpack.tf/item/7348382797 - 7 keys

https://backpack.tf/item/6264086455 - marketplace

https://backpack.tf/item/6819060720 - marketplace

https://backpack.tf/item/6258669838 - marketplace

https://backpack.tf/item/8597052535 - marketplace

https://backpack.tf/item/6916872264 - marketplace

Sales at:

2.2

2.8

3

3.2

3.45

Buyers up to 2.85 keys, excluding 2.2 and 2.8.

Taking 3-3.45 keys.