History 1: https://backpack.tf/item/7292574712

6 keys 2 ref, ~6 keys:

https://backpack.tf/profiles/76561199106217370#!/compare/1608854400/1608940800

https://backpack.tf/profiles/76561198174932630#!/compare/1608681600/1610668800

History 2: https://backpack.tf/item/7284765557

The Strange Flared Frontiersman matches, more was possibly involved but this alone will be around buy order price

https://backpack.tf/profiles/76561198453530349#!/compare/1611100800/1611187200

https://backpack.tf/profiles/76561197981022996#!/compare/1611100800/1612310400

History 3: https://backpack.tf/item/7254403558

Sold to a quickbuyer:

https://backpack.tf/profiles/76561197969363424#!/compare/1613952000/1614038400

https://backpack.tf/profiles/76561198841279602#!/compare/1613865600/1613952000

21 ref matches in seller's compare, 5 keys match in buyer's compare:

https://backpack.tf/profiles/76561198841279602#!/compare/1615852800/1615939200

https://backpack.tf/profiles/76561198122894683#!/compare/1615852800/1615939200

Buyout was 5 keys 31.77 ref https://gladiator.tf/listings/604fd93692cfe49b4316fa35

Can't trace the full 31.77 ref but in both cases this sale will round to 5.5

History 4: https://backpack.tf/item/7183513452

Untraceable:

https://backpack.tf/profiles/76561198025006537#!/compare/1610582400/1610668800

https://backpack.tf/profiles/76561197963500354#!/compare/1610582400/1610668800

Marketplace.tf sale: https://marketplace.tf/items/tf2/30671;5;u3018

January 11: $23/2.12=10.85 ~11 keys

Mannco.Store sale: https://mannco.store/item/27223

Janaury 3: $13.99/1.85=7.56 ~7.5 keys

Unsolds:

8 keys for 3 days https://backpack.tf/item/7183513452

10 keys for 6 months https://backpack.tf/item/7222851015

Sales at 5.5, 6, 7.5, 11

Given both unsolds, especially the one at 10 for 6 months, there' no way the sale at 11 should be included.

Gonna go with 5.5-7.5