Thank you Shuffle Spy for the extra information provided for this New Price Suggestion.

Bought for 6 keys and a 3.3 key Strange War Pig:

https://backpack.tf/profiles/76561198059098316#!/compare/1559001600/1559088000

Mini for the War Pig:

https://imgur.com/a/EsiETr9

Sale Orders at 3.43 keys

Buy Orders at 2.55 - 3 keys

Bp.tf price at 3.3 keys looks up to date.

https://backpack.tf/profiles/76561198381480639#!/compare/1557360000/1557446400 - SCM purchase

https://steamcommunity.com/market/listings/440/Unusual%20Mighty%20Mitre - The only 2 sales on 5/9 - 5/10 are both $21.27, so I think it's one of those

Keys were ~$2.28 at the time, so this sale is ~9.3 Keys also

https://backpack.tf/profiles/76561198102068252#!/compare/1557964800/1558051200 - Quicksold for 10 Keys

https://backpack.tf/profiles/76561198389884237#!/compare/1557878400/1558051200 - Buyer's side

2 for sale at 19$ on the Mannco.store

https://mannco.store/item/10801