Marketplace Sales:

https://marketplace.tf/items/tf2/31236;5;u3120

$4.49, August 30th, Sept 2nd (2x), Sept 5th, Sept 7th

$4.99, Sept 9th (2x)

https://backpack.tf/item/12444796996

https://backpack.tf/item/12489619542

https://backpack.tf/item/13310864862

https://backpack.tf/item/13524958304

https://backpack.tf/item/12498877954

https://backpack.tf/item/12265184944

Histories displayed in the order of oldest sales to newest, though 1 history is missing. The first one, which is most likely the August 30th sale, resold to a bot.

https://marketplace.tf/items/tf2/5021;6 - keys were:

$1.81, August 30th

$1.82, Sept 2nd & 9th

$1.80, Sept 5th & 7th

4.49/1.81 = 2.481, rounds to 2.5 keys

4.49/1.82 = 2.467, rounds to 2.45 keys (2x)

4.49/1.8 = 2.494, rounds to 2.5 keys (2x)

4.99/1.82 = 2.742, rounds to 2.75 keys (2x)

Other Sales:

https://backpack.tf/profiles/76561199211253352#!/compare/1756771200/1761868800

https://backpack.tf/profiles/76561199203680409#!/compare/1761436800/1761523200

https://backpack.tf/item/12444796996

Bulk/untraceable

https://backpack.tf/item/12416049660 - quicksell.store

https://backpack.tf/item/12422653202 - quicksell.store

https://backpack.tf/item/12428343069 - quicksell.store

https://backpack.tf/item/13241803678 - account transfers or something

Sellers:

https://i.imgur.com/HCQQICa.png

https://backpack.tf/item/12444796996 - ~2.55 keys

https://backpack.tf/item/13319540677 - ~2.95 keys

https://backpack.tf/item/12457078320 - ~2.95 keys

https://backpack.tf/item/12265184950 - $25

Sales at:

2.45 (2x)

2.5 (3x)

2.75 (2x)

Seller at 2.55 isn’t enough to counter the sales at 2.75, keeping 2.75 in the range.

Taking 2.45-2.75.