Sale 1:

https://backpack.tf/profiles/76561198985910282#!/compare/1586390400/1586476800

https://backpack.tf/profiles/76561198817647410#!/compare/1586390400/1586476800

https://backpack.tf/profiles/76561198363395191#!/compare/1586563200/1586649600

Bought and QS within a few days.

sale 2:

https://backpack.tf/profiles/76561198363395191#!/compare/1586736000/1586822400

https://backpack.tf/profiles/76561198124830003#!/compare/1586908800/1587427200

untrace

sale 3:

https://backpack.tf/profiles/76561198985910282#!/compare/1586563200/1586649600

https://backpack.tf/profiles/76561198259500466#!/compare/1586649600/1586736000

Sold for ~8.5 keys

sale 4:

https://backpack.tf/profiles/76561198147927648#!/compare/1584748800/1585094400

https://backpack.tf/profiles/76561198021055079#!/compare/1584748800/1584921600

Bulk

sale 5:

https://backpack.tf/profiles/76561198021055079#!/compare/1589328000/1589414400

https://backpack.tf/profiles/76561198052194031#!/compare/1589328000/1589414400

Sold for Stormy Beanie

use there

https://bot.tf/stats/listings/4P0DVRNZ

B/O of 10 keys

Sale 6:

https://backpack.tf/profiles/76561198052194031#!/compare/1589414400/1589500800

https://backpack.tf/profiles/76561198158347026#!/compare/1589414400/1589500800

Sold with negligible sweets for C9 Airdog

Airdog Mini:

https://backpack.tf/suggestion/5ebef87253466a1b8b310dab

Suggestion for 10.5 keys

Total is ~10 keys

https://bot.tf/stats/listings/Y5Z9JOL2

B/O of 11 keys

sale 7:

https://backpack.tf/profiles/76561198158347026#!/compare/1589414400/1589500800

https://backpack.tf/profiles/76561198272038643#!/compare/1589414400/1589500800

Sold for ~8 keys

Sale 8:

https://marketplace.tf/items/tf2/388;5;u60;strange

$19.95 / $1.72 = 11.60 keys <--- https://backpack.tf/item/7957014034

Sale 9:

https://marketplace.tf/items/tf2/388;5;u60

$17.95 / $1.79 = 10.03 keys

Total sales @:

8, 8.5, 10, 10, 12 keys

buyers up to ~8.28 keys,

sellers at 10 keys,

taking 8.5 - 10 keys