Sale 1-3:

https://marketplace.tf/items/tf2/30958;5;u17

$35 / $1.70 = 20.59 keys

$49.99 / $1.79 = 27.93 keys // https://backpack.tf/item/6489325705

$49.99 / $1.81 = 27.62 keys // https://backpack.tf/item/6473492914

Sale 4:

untrace

https://backpack.tf/profiles/76561197992703391#!/compare/1571270400/1571356800

https://backpack.tf/profiles/76561198089253101#!/compare/1571270400/1571356800

Sale 5:

untrace - possibly mp sale 2

https://backpack.tf/profiles/76561198089253101#!/compare/1575676800/1575763200

https://backpack.tf/profiles/76561198114644154#!/compare/1576108800/1577404800

Sale 6:

bulk

https://backpack.tf/profiles/76561198114644154#!/compare/1577404800/1577491200

https://backpack.tf/profiles/76561198084367252#!/compare/1577404800/1577491200

Sale 7:

untrace

some keys in the group of 47 match but thats way too high so idk

https://backpack.tf/profiles/76561198002757046#!/compare/1571788800/1571875200

https://backpack.tf/profiles/76561198430115725#!/compare/1571702400/1571875200

Sale 8:

with CHeart VRH for keys

https://backpack.tf/profiles/76561198079007530#!/compare/1574294400/1574726400

https://backpack.tf/profiles/76561198859721638#!/compare/1574640000/1574726400

Sale 9:

PE Raincatcher(25) + 4 keys

https://backpack.tf/profiles/76561198859721638#!/compare/1574812800/1574899200

https://backpack.tf/profiles/76561198113771976#!/compare/1574812800/1574899200

raincatcher: https://backpack.tf/suggestion/5e20cdb012853c3838596673

Sale 10:

26 pure

https://backpack.tf/profiles/76561198113771976#!/compare/1575158400/1575936000

https://backpack.tf/profiles/76561198106645651#!/compare/1575849600/1575936000

Sale 11:

23 keys

CPS Hermes(11) + miami nights Conquistador(9) + 3 keys

https://backpack.tf/profiles/76561198106645651#!/compare/1575936000/1576281600

https://backpack.tf/profiles/76561198258055271#!/compare/1576195200/1576281600

hermes: https://backpack.tf/suggestion/5e20d8f2fd79d33a862e0136

Conquistador: https://backpack.tf/suggestion/5e20e34d4b013020e33b0eff

Sale 12:

Scorching Capotain

buyers at capotain at 29 means this will be too high

https://backpack.tf/profiles/76561198258055271#!/compare/1576281600/1576368000

https://backpack.tf/profiles/76561198073374621#!/compare/1576281600/1576368000

Sale 13:

untrace

https://backpack.tf/profiles/76561198073374621#!/compare/1576886400/1579132800

https://backpack.tf/profiles/76561198125791160#!/compare/1576886400/1576972800

Sale 14:

~25 keys

24 keys + 60 ref

https://backpack.tf/profiles/76561198125791160#!/compare/1578441600/1578528000

https://backpack.tf/profiles/76561198126675787#!/compare/1578528000/1578700800

Sale 15:

30 pure

https://imgur.com/a/AEqWrEu

https://backpack.tf/profiles/76561198166655344#!/compare/1569888000/1579132800

https://backpack.tf/profiles/76561198084367252#!/compare/1579046400/1579132800

==============================================================================

Sales:

21,23,25,26,28,28,29,30