Credits to Greedz and Xergoyf

https://backpack.tf/item/2055793062

Xergoyf stated Slobek bought for bulk cash:

https://backpack.tf/profiles/76561198275478002#!/compare/1634774400/1634860800

https://backpack.tf/profiles/76561198258937500#!/compare/1634774400/1634860800

Greedz stated Jezzus' purchase was

https://imgur.com/a/r9SW2oj

625 keys + Cursed Confinement Taunt: The Fist Bump (11) = 636, ~635

[Mini for Fist (Xergoyf):

https://marketplace.tf/items/tf2/31162;5;u3060

$29.99 / $1.83 = 16.39 keys (x2)

$19.99 / $1.83 = 10.92 keys (x7)

16 sales are too high given the sellers at 12/13 atm. 11 flat will be fine as a mini.]

Greedz's sale:

https://backpack.tf/profiles/76561198258937500#!/compare/1640649600/1640736000

https://backpack.tf/profiles/76561198075415934#!/compare/1640649600/1640736000

Screenshot of agreement: https://imgur.com/a/IpSmfYO

Screenshot of trade offer: https://imgur.com/a/0IlErBy

780 keys + Creepy Crawlies Taunt: Buy A Life (buyers at ~3 https://gladiator.tf/listings/62332d4f035fc862c45d3f03) = 783, ~780

Sales:

635, 780

Taking 635-780 as Xergoyf suggested.