Resuggestion, thanks to MTC for the info!

Sale 1:

https://backpack.tf/profiles/76561198341171690#!/compare/1585699200/1585785600

https://backpack.tf/profiles/76561198022617618#!/compare/1585785600/1585872000

Sold for 9 keys

Sale 2:

https://backpack.tf/profiles/76561198067946118#!/compare/1590969600/1591056000

https://backpack.tf/profiles/76561198106112825#!/compare/1590969600/1591056000

Sold for ~6.5 keys

Sale 3:

https://backpack.tf/profiles/76561198106112825#!/compare/1590969600/1591056000

https://backpack.tf/profiles/76561198104056646#!/compare/1591056000/1591142400

Sold for Abduction HFOHA + 1 key

use there, caps here easily, as by buyers the sale is 9.5 keys.

https://bot.tf/stats/listings/4R03J77D

B/O of 10 keys

Sale 4:

https://backpack.tf/profiles/76561198104056646#!/compare/1591056000/1591142400

https://backpack.tf/profiles/76561198183693709#!/compare/1591056000/1591142400

https://backpack.tf/profiles/76561198850178158#!/compare/1591056000/1591142400

Keys, then bulk

sale 5:

https://backpack.tf/profiles/76561198850178158#!/compare/1592438400/1592524800

https://backpack.tf/profiles/76561198183693709#!/compare/1592352000/1592524800

Sold for ~10 keys

buyers up to ~9.31 keys,

MTC's Part:

https://backpack.tf/profiles/76561198095022965#!/compare/1591315200/1591401600 - compare

https://i.imgur.com/GHBLQFX.gifv - screenshot

https://backpack.tf/profiles/76561198086747482 - his profile

https://backpack.tf/item/7988606261 - history

Sold for 28.14 euro,

keys at ~2.24 Euro,

Total is ~12.5625 keys

Taking 10 - 13 keys.