Resuggestion, thx to multiple people (I'll mention them when I show their help)

Marketplace.tf sale (untraceable history): https://marketplace.tf/items/tf2/17236;5;u702;w3;pk236

February 8: $149.99/2.13=70.42 ~70 keys

(Credit to Offline) Item history: https://backpack.tf/item/9715243012

https://backpack.tf/profiles/76561198126201253#!/compare/1610668800/1611100800

https://backpack.tf/profiles/76561198064658655#!/compare/1611014400/1611100800

https://gyazo.com/102a6cc198943a64b2c44204a0ff40fd

Bought for 40 keys buy order

https://backpack.tf/profiles/76561199100906514#!/compare/1612483200/1612569600

https://backpack.tf/profiles/76561198064658655#!/compare/1612483200/1612569600

https://backpack.tf/profiles/76561198091502579#!/compare/1612483200/1612569600

https://gyazo.com/707f90919b00038de577919c4cc1088a

Sold in bulk to Erik, and Erik sold it on Marketplace

(Credit to aj) https://backpack.tf/item/9366917143

https://backpack.tf/profiles/76561198209640976#!/compare/1612828800/1612915200

Buyout of 70 keys: https://prnt.sc/ywcury

This sale is PE Bat Hat + 30 keys

(Credit to BlazingHailfire for the screenshot) https://cdn.discordapp.com/attachments/774732818529255455/810171330359459890/unknown.png

PE Bat Hat mini (mean of 32.5 ~33 keys): https://backpack.tf/suggestion/60280944d367133efe2378c3

30+33=63 keys, doesn't cap the buyout

Sales at 40, 63, 70

40 was dumped to a buy order, going 63-70