Resuggestion, thanks to Randy & Jarool for the info!

Sale 1:

https://backpack.tf/profiles/76561198023051867#!/compare/1535068800/1535155200

https://backpack.tf/profiles/76561198124934893#!/compare/1535068800/1535587200

Untrace.

Sale 2:

https://backpack.tf/profiles/76561198123631904#!/compare/1533686400/1534464000

Bulk.

Sale 3:

https://backpack.tf/profiles/76561198058266974#!/compare/1531526400/1531785600

https://backpack.tf/profiles/76561198031511569#!/compare/1529366400/1531612800

Untrace.

Sale 4:

https://backpack.tf/profiles/76561198075551260#!/compare/1532304000/1532476800

Bulk.

Sale 5:

https://backpack.tf/profiles/76561198037171335#!/compare/1530835200/1530921600

https://backpack.tf/profiles/76561198148495750#!/compare/1530835200/1530921600

Bulk.

Sale 6:

https://backpack.tf/profiles/76561198148495750#!/compare/1531267200/1531353600

Untrace / Bulk

Sale 7:

https://backpack.tf/profiles/76561198011894731#!/compare/1531353600/1531440000

Untrace.

Sale 8:

https://backpack.tf/profiles/76561198190042470#!/compare/1532304000/1532736000

https://backpack.tf/profiles/76561198039427856#!/compare/1532304000/1532563200

https://backpack.tf/profiles/76561198037171335#!/compare/1532304000/1532390400

Untrace, but sold for 7 keys at the end.

Sale 9, 10, 11, 12:

https://marketplace.tf/items/30609;5;u3005

Sold for 19.52, 18.99, 24.99, 24.99 USD

Keys at 1.89, 1.88, 1.88, 1.88 USD

Totals are 10.33, 10.10, 13.29, 13.29 keys

Jarool's Part:

sold for 7 keys

https://backpack.tf/profiles/76561198125791160#!/compare/1536364800/1536451200

https://backpack.tf/profiles/76561198404091129#!/compare/1536451200/1537660800

sold for 9 keys

https://backpack.tf/profiles/76561198305676157#!/compare/1537488000/1537574400

https://backpack.tf/profiles/76561198064104470#!/compare/1532217600/1537920000

https://backpack.tf/item/7177266046

https://backpack.tf/item/7177266052

https://backpack.tf/item/7177266056

https://backpack.tf/item/7177266068

https://backpack.tf/item/7177266075

https://backpack.tf/item/7177266078

https://backpack.tf/item/7177266084

https://backpack.tf/item/7177266086

https://backpack.tf/item/7177266089

Randy's Part:

so how I'm seeing it rn is that while a seller at 7 yeah its at a week but with 3-4 recent enough sales at 9-10 its basically the same amount of sales we got at 7. It wouldn't be right imo to exclude them being so close and having multiple sales at both ends. 7-10 as a range is prolly best here.

Taking 7 - 10 keys