Sale 1:

https://backpack.tf/profiles/76561198100128947#!/compare/1621987200/1622073600

https://backpack.tf/profiles/76561198365295882#!/compare/1621987200/1622073600

Sold for Strange Specialized Killstreak Australium Ambassador (https://gladiator.tf/listings/60aea726f6b6958734e7f54c - 13k) + Strange Specialized Killstreak Conniver's Kunai (https://gladiator.tf/listings/60aea72c8d621a8985253ed2 - 2k 40ref) + around 40 ref in mixed = 16.38 Keys.

= 16 Keys.

Sale 2:

https://backpack.tf/profiles/76561198365295882#!/compare/1622505600/1622764800

https://backpack.tf/profiles/76561198403706199#!/compare/1622678400/1622764800

Untrace.

Sale 3:

https://backpack.tf/profiles/76561198403706199#!/compare/1622678400/1622764800

https://backpack.tf/profiles/76561199068665221#!/compare/1622678400/1622764800

= 15 Keys.

Sale 4:

https://backpack.tf/profiles/76561199068665221#!/compare/1623628800/1623715200

https://backpack.tf/profiles/76561198142822631#!/compare/1623369600/1623628800

= 14 Keys. ( Shuffle: https://backpack.tf/suggestion/60cc8580f2c1ab2a003b8256#comment-60f4e2d788c67764183e6717 )

Sale 5:

https://backpack.tf/profiles/76561198142822631#!/compare/1623628800/1623715200

https://backpack.tf/profiles/76561198453530349#!/compare/1623628800/1623715200

= 10 Keys. (QS)

Sale 6:

https://backpack.tf/profiles/76561198453530349#!/compare/1623715200/1623801600

https://backpack.tf/profiles/76561199125443371#!/compare/1623628800/1623715200

Untrace.

Sale 7:

https://backpack.tf/profiles/76561199125443371#!/compare/1623801600/1623888000

https://backpack.tf/profiles/76561198053720151#!/compare/1623801600/1623888000

= 16 Keys.

Sales: 10, 14, 15, 16, 16

Shuffle Spy: https://backpack.tf/suggestion/60cc8580f2c1ab2a003b8256#comment-60f4e2d788c67764183e6717

https://backpack.tf/profiles/76561198053720151#!/compare/1624060800/1624147200 - Bulk

https://marketplace.tf/items/tf2/108;5;u65 - $55 (high)

I can count 14 Keys in sale 2 from the buyer's compare. Since 30 Refined got added for the 15 Keys in sale 3, that sale is actually 14 Keys.

14 to 16 would work here.