Oh, forgot this one.

SALE 1

Sold for keys, not sure how many though.

https://backpack.tf/profiles/76561198802802073#!/compare/1563408000/1563667200

https://backpack.tf/profiles/76561198100836666#!/compare/1563580800/1563667200

SALE 2

Sold for atleast 1 key

https://backpack.tf/profiles/76561198802802073#!/compare/1563667200/1563753600

https://backpack.tf/profiles/76561198319589832#!/compare/1563667200/1563753600

SALE 3

Sold for 13 keys

https://backpack.tf/profiles/76561198319589832#!/compare/1563580800/1563667200

https://backpack.tf/profiles/76561198200696439#!/compare/1563580800/1563667200

SALE 4

Sold for 22 keys + 2 refined

https://backpack.tf/profiles/76561198359746121#!/compare/1563753600/1563840000

https://backpack.tf/profiles/76561198200696439#!/compare/1563840000/1563926400

Rounding to 22 keys.

Excluding as it was dumped to SALE 5.

SALE 5

Sold for 18 keys + 16 refined + items worth up to 15.33 refined

https://backpack.tf/profiles/76561198359746121#!/compare/1564531200/1564617600

https://backpack.tf/profiles/76561198154109244#!/compare/1564531200/1564617600

Rounds to 19 keys.

Excluding due to being a dumped sale, see SALE 4.

SALE 6

Sold with 24 keys for clairvoyance defragmenting hard hat

https://backpack.tf/profiles/76561198154109244#!/compare/1564531200/1564617600

https://backpack.tf/profiles/76561198148836514#!/compare/1564531200/1564617600

Hard hat is indate.

53 - 24 = 29 keys

SALE 7

Not sure

https://backpack.tf/profiles/76561198148836514#!/compare/1564704000/1564876800

https://backpack.tf/profiles/76561198105098440#!/compare/1563321600/1565395200

SALE 8, 9 & 10

49.99 on july 27 (49.99/1.78 = 28.08 rounding to 28 keys)

39.06 on august 4 (39.06/1.84 = 21.22 rounding to 21 keys)

49.98 on august 10 (49.98/1.81 = 27.61 rounding to 27 keys)

https://marketplace.tf/items/tf2/229;5;u9

Item history of SALE 8: https://backpack.tf/item/424698088

SALE 11

Sold for 25 keys

https://backpack.tf/profiles/76561198349886701#!/compare/1562457600/1562544000

https://backpack.tf/profiles/76561198059482524#!/compare/1562371200/1562457600

CLASSIFIEDS

https://gyazo.com/efc42e0d3898b6d3d04d99db1ad518bf

Sales at 13, 25 and 29. Marketplace sales at 21, 27, and 28.

Taking 21-29 keys.