History 1: https://backpack.tf/item/9690835405

28 keys:

https://backpack.tf/profiles/76561198040073503#!/compare/1639353600/1639785600

https://backpack.tf/profiles/76561198965070085#!/compare/1639612800/1639699200

History 2: https://backpack.tf/item/8368523155

14 keys + Strange Professional Killstreak Festive Gloves of Running Urgently + Spelled Strange Rust Botkiller Minigun Mk.I + Spelled Strange Carbonado Botkiller Flame Thrower Mk.I

+ Double Spelled Haunted Birdie Bonnet:

https://backpack.tf/profiles/76561198063029136#!/compare/1632614400/1632700800

https://backpack.tf/profiles/76561198042027077#!/compare/1632614400/1632700800

The Minigun doesn't have any usable sales, but 1 key should be a reasonable estimation, since the majority of Stranges with Exorcism go for ~1 key

The gloves are ~4 keys https://gladiator.tf/sales?item=Strange%20Professional%20Killstreak%20Festive%20Gloves%20of%20Running%20Urgently&at=2021-09-26T10:12:52.136Z

Spelled FT re-sold at 6 keys https://backpack.tf/profiles/76561198063029136#!/compare/1632873600/1632960000

The Birdie Bonnet doesn't have any usable sales either, but this sale will cap at the 25 key buyout without including it (the rest already adds to 25) https://gladiator.tf/listings/61509bdd6735ef4fd9922b68

taking 25-28 keys here