https://backpack.tf/profiles/76561198331327749#!/compare/1630022400/1630368000 - Sold for 5 keys + Warpaint (~5 keys) = 10 keys

https://backpack.tf/profiles/76561198120774019#!/compare/1631923200/1632009600 - Sold for 10 keys

https://backpack.tf/profiles/76561198107289351#!/compare/1631059200/1631145600 - Sold with sweets for a Resonation Snack Stack, better there

https://backpack.tf/profiles/76561198376885782#!/compare/1630627200/1630713600

https://backpack.tf/profiles/76561198107289351#!/compare/1630627200/1630713600 - Sold for 5 keys + ~5 keys in sweets = 10 keys

https://backpack.tf/profiles/76561198956272094#!/compare/1630454400/1630540800

https://backpack.tf/profiles/76561198376885782#!/compare/1630454400/1630540800 - Untrace

https://backpack.tf/profiles/76561198129850865#!/compare/1630195200/1630281600 - Untrace

https://backpack.tf/profiles/76561198249207818#!/compare/1628985600/1630713600 - Untrace

https://marketplace.tf/items/tf2/31197;5;u18 - Seems high

https://backpack.tf/profiles/76561198079990847#!/compare/1626480000/1626566400

https://backpack.tf/profiles/76561198405776775#!/compare/1619481600/1631577600 - Untrace

https://mannco.store/item/440-circling-peace-sign-unusual-fried-batter

$18.98 / $1.68 = 11 keys

Since there's so many sales at 10 and a few lower sales to support 9, this will be close. Calling the cash sale high. Accepting :D