Item 1:

https://backpack.tf/item/3418912278

Sale 1:

https://backpack.tf/profiles/76561199564942025#!/compare/1762646400/1762732800

https://backpack.tf/profiles/76561199072652703#!/compare/1762646400/1762732800

Sold between STN and Scrapyard bots, no clue

Sale 2:

https://backpack.tf/profiles/76561199072652703#!/compare/1763251200/1763337600

https://backpack.tf/profiles/76561198775376883#!/compare/1763078400/1763337600

Sold for 150 keys pure (ID 16414143353)

Sale 3:

https://backpack.tf/profiles/76561198775376883#!/compare/1763337600/1763510400

https://backpack.tf/profiles/76561198453530349#!/compare/1763424000/1763510400

Dumped for 132 keys + some ref (ID 16418239796)

Item 2:

https://backpack.tf/item/2315815092

Sale 4:

https://backpack.tf/profiles/76561199161718959#!/compare/1760140800/1760400000

https://backpack.tf/profiles/76561198972819013#!/compare/1760313600/1760400000

Bulk for Cloudy Moon Magistrate's Mullet

Sale 5:

https://backpack.tf/profiles/76561198972819013#!/compare/1761091200/1761177600

https://backpack.tf/profiles/76561198206623061#!/compare/1760745600/1761177600

Sold for a Voices from Below + Rotten Orange Footprints Bill's Hat + Exorcism Strange Professional Killstreak Powerjack + Exorcism and Halloween fire Strange Professional Killstreak Degreaser

Couldn't find any valid mini (no clear buyers either) for the bills, buyers for the degreaser are around 61 keys. However excluding this sale due to it being dumped a day later as per sale 6

Sale 6:

https://backpack.tf/profiles/76561198206623061#!/compare/1761350400/1761523200

https://backpack.tf/profiles/76561199509832207#!/compare/1761436800/1761523200

Untrace, however was dumped to a bot

Sale 7:

https://backpack.tf/profiles/76561199509832207#!/compare/1761436800/1761523200

https://backpack.tf/profiles/76561199132665029#!/compare/1761350400/1761436800

Sold between bots, untrace

Then listed on MP

Item 3:

https://backpack.tf/item/274219041

Sale 8:

https://backpack.tf/profiles/76561198083134207#!/compare/1767398400/1767484800

https://backpack.tf/profiles/76561198024321232#!/compare/1767398400/1767484800

https://imgur.com/a/iKqzON8 - Credits Catfood

Sold for 140 keys pure

Item 4:

https://backpack.tf/item/176643851

Listed on MP

//

Sellers:

BPTF - https://imgur.com/a/3kuLvQs - 2 @ 144, 1 @ 150, 1 listed on MP as per below

MPTF - https://marketplace.tf/items/tf2/108;5;u13 - 3 @ $275.50 (~150)

STN - https://stntrading.eu/item/tf2/Unusual+Burning+Flames+Backbiter%27s+Billycock - None

SCM - https://steamcommunity.com/market/listings/440/Unusual%20Backbiter%27s%20Billycock?filter=Burning+Flames - None

Sale(s):

150, 132, 140

Considering the 150 was then dumped 132 just under 2 months later excluding both from the range. Not to mention there is 2 unsolds for less (144 unsold for 3 months, granted it is duped but still). Additionally 132 is now countered by buyers (STN buying for 138)

The spelled sale also could have been used if there was a valid minis for each however again because it was dumped straight away I am excluding it.

Going with 140 keys flat