Not sure I'm a fan of the "11" sale since it was sold back to quicksell.store today, plus the KAW Baron Plane https://backpack.tf/item/1995941099 matches, making the sale bulkish

The buyer of the marketplace.tf sale resold to buyers too

Couple of missed sales:

https://backpack.tf/profiles/76561198825943127#!/compare/1629590400/1629936000 - Sold via buy order

https://gladiator.tf/listings/612102073a0829f7e28e2355 - Likely for ~9 keys

https://backpack.tf/profiles/76561198825943127#!/compare/1627171200/1627257600

https://backpack.tf/profiles/76561198273331466#!/compare/1627171200/1627257600 - Bulk

https://backpack.tf/profiles/76561198453530349#!/compare/1625875200/1625961600 - Buy order, likely for ~8.5 keys https://gladiator.tf/listings/60e9fd8142b2b2179b853777

https://backpack.tf/profiles/76561198412710098#!/compare/1625875200/1625961600 - Bulk

Sales in total,

8.5, 9, 10, 10.49

I would take 8.5 - 10 here

8.5 is also supported by the marketplace.tf sale reselling to buy orders (potentially around this value)

I would round 10.49 to 10 even though the mid-point is below 10 keys here, since it's supported by 10.49 reselling for lower.