Thanks go to Shuffle Spy, gege and Mr365truck for helping with finding sales and giving tips.

https://backpack.tf/profiles/76561198135737005#!/compare/1611014400/1611100800

https://backpack.tf/profiles/76561198018055115#!/compare/1608595200/1611273600 - 21 keys.

https://backpack.tf/profiles/76561198109756155#!/compare/1610236800/1610323200 - Bulk

https://backpack.tf/profiles/76561198135737005#!/compare/1610150400/1610409600 - Grenadier's Softcap (17 keys)

https://gladiator.tf/listings/5ffbea0d1b867573cafa045b - The Softcap went for ~17 Keys at the time of the sale

https://backpack.tf/profiles/76561198043525662#!/compare/1607212800/1607472000 - Backpack dump

https://backpack.tf/profiles/76561198990190854#!/compare/1606953600/1607299200 - Untraceable

https://backpack.tf/profiles/76561198019842645#!/compare/1615248000/1615334400 - Untraceable

https://backpack.tf/profiles/76561198094059650#!/compare/1609113600/1609200000 - Added 3 Keys for a Green Energy Brain-Warming Wear (19 Keys)

https://imgur.com/a/uNgfKIE

https://imgur.com/a/cOvmv5J - one confirmed sale on SCM on January 24th for 198 PLN (keys were 9.22 PLN at the time). Rounding 21.55 keys to 22. More info about the SCM sale available here: https://backpack.tf/suggestion/600ac13e181dd2030d1b9581

https://marketplace.tf/items/tf2/30922;5;u3042 No marketplace.tf sales since December 1st.

Taking 16-22 keys.