Resuggesting, thanks to Blaze for the info!

Sale 1:

https://backpack.tf/profiles/76561198105071091#!/compare/1541030400/1541116800

https://backpack.tf/profiles/76561198184671851#!/compare/1541030400/1541116800

Untrace

Sale 2:

https://backpack.tf/profiles/76561198184671851#!/compare/1541203200/1541462400

https://backpack.tf/profiles/76561198372942066#!/compare/1541116800/1541462400

Untrace

Sale 3:

https://backpack.tf/profiles/76561198372942066#!/compare/1541894400/1541980800

https://backpack.tf/profiles/76561198142892266#!/compare/1541808000/1541894400

Bulk

Sale 4:

https://backpack.tf/profiles/76561198142892266#!/compare/1541894400/1541980800

https://backpack.tf/profiles/76561198103918688#!/compare/1541721600/1541894400

Untrace

Sale 5:

https://backpack.tf/profiles/76561198103918688#!/compare/1541894400/1542067200

https://backpack.tf/profiles/76561198081537862#!/compare/1541894400/1541980800

Untrace

Sale 6:

https://backpack.tf/profiles/76561198800685443#!/compare/1544140800/1544227200

https://backpack.tf/profiles/76561198160120451#!/compare/1544054400/1544140800

Bulk

Sale 7:

https://backpack.tf/profiles/76561198405542961#!/compare/1544313600/1544400000

https://backpack.tf/profiles/76561198329719416#!/compare/1543708800/1544400000

Untrace

Sale 8:

https://backpack.tf/profiles/76561198329719416#!/compare/1545436800/1547251200

https://backpack.tf/profiles/76561198026487542#!/compare/1545004800/1545436800

End up low

Sale 9, 10, 11:

https://marketplace.tf/items/615;5;u33

Sold for 21.95, 18.99, 25.94 USD

Keys at 1.78, 1.77, 1.68 USD

Totals are 12.33, 10.72, 15.72 keys

Sale 12:

https://backpack.tf/profiles/76561198117281299#!/compare/1542326400/1548633600

https://backpack.tf/profiles/76561198197686845#!/compare/1548547200/1548633600

Sold for ~10 keys

Sale 13:

https://backpack.tf/profiles/76561198197686845#!/compare/1548547200/1548633600

https://backpack.tf/profiles/76561198344316001#!/compare/1548547200/1548633600

Untrace

Sale 14:

https://backpack.tf/profiles/76561198344316001#!/compare/1548720000/1548806400

https://backpack.tf/profiles/76561198372525896#!/compare/1548720000/1548806400

Untrace

Blaze's Part:

with sales at 10, 11, 12, 16 now, 16 should be considered an outlier here given it is pretty far away from the other sales

Buyers up to 9 keys,

10 was immediatly sold afterwards,

Taking 11 - 12 keys