Credits to Blaze:

https://marketplace.tf/items/tf2/1172;5;u3001 - new sales at $29.99 (high)

https://gladiator.tf/sales?item=Showstopper%20Taunt:%20The%20Victory%20Lap&at=2022-03-30T16:55:26.398Z - sales at 12~, 12~, 15~

https://backpack.tf/profiles/76561198311498888#!/compare/1646179200/1646265600 - sold for 14 keys

https://backpack.tf/profiles/76561198154693878#!/compare/1638144000/1647820800 - bulk

https://backpack.tf/profiles/76561198118157202#!/compare/1644624000/1644710400

https://backpack.tf/profiles/76561199128560410#!/compare/1644624000/1644710400 - sold for 13 keys

https://backpack.tf/profiles/76561198043814643#!/compare/1644537600/1644883200

https://backpack.tf/profiles/76561198074718149#!/compare/1644451200/1644537600 - bulk

https://backpack.tf/profiles/76561199065720756#!/compare/1644364800/1644451200

https://backpack.tf/profiles/76561198043814643#!/compare/1644364800/1644451200 - bulk

https://backpack.tf/profiles/76561198275478002#!/compare/1644710400/1644796800

https://backpack.tf/profiles/76561198216241727#!/compare/1644710400/1644796800 - sold for 15 keys

https://backpack.tf/profiles/76561198426744204#!/compare/1643673600/1648166400

https://backpack.tf/profiles/76561198387793458#!/compare/1646006400/1648166400 - bulk

https://backpack.tf/profiles/76561198274797164#!/compare/1646611200/1646697600

https://backpack.tf/profiles/76561198057897812#!/compare/1646524800/1646611200 - bulk

Month 1 https://gladiator.tf/sales?item=Showstopper%20Taunt:%20The%20Victory%20Lap&at=2022-02-12T13:28:51.259Z

1 @ 14 keys 9.33 ref

1 @ 14 keys 20.66 ref

1 @ 15 keys

Month 2 https://gladiator.tf/sales?item=Showstopper%20Taunt:%20The%20Victory%20Lap&at=2022-01-12T13:28:51.259Z

1 @ 15 keys 66 ref

Month 3 https://gladiator.tf/sales?item=Showstopper%20Taunt:%20The%20Victory%20Lap&at=2021-12-12T13:28:51.259Z

1 @ 14 keys 37.44 ref

https://marketplace.tf/items/tf2/1172;5;u3001

$29.99 / $1.91 = 15.70 keys

$29.99 / $1.83 = 16.39 keys

$29.99 / $1.83 = 16.39 keys

$29.99 / $1.82 = 16.48 keys

https://mannco.store/item/440-showstopper-unusual-taunt-the-victory-lap

$25 / $1.67 = 14.97 keys

$33.33 / $1.61 = 20.70 keys

Classies: https://gladiator.tf/listings/6244b66ef7f77cbde9eeb7b5

Page of sellers now 15 and below, buyers at 12+

New sellers indicate sales 16 and above should be excluded. Since these higher sales are being excluded, 12 (essentially at buy orders) should be also to balance the range a bit better.

13-15.