Taking last 2 months

theres 9 sales of these on marketplace for $39.99 and 8 of them are mine

https://marketplace.tf/items/tf2/31186;5;u186

Sep 14 - $39.99 / $1.84 = 21.73 keys

Sep 19 - $39.99 / $1.84 = 21.73 keys

Sep 29 - $39.99 / $1.83 = 21.85 keys

Oct 27 - $39.99 / $1.87 = 21.39 keys

Nov 4 - $39.99 / $1.87 = 21.39 keys

Nov 5 - $39.99 / $1.87 = 21.39 keys

https://backpack.tf/profiles/76561198939016803#!/compare/1630972800/1631404800

https://backpack.tf/profiles/76561198064658655#!/compare/1630886400/1630972800

https://gyazo.com/34bd859179ec65c8d071a12d1001b2ac

17.5 keys to buy order

https://backpack.tf/profiles/76561198188093413#!/compare/1632268800/1632355200

https://backpack.tf/profiles/76561198868936983#!/compare/1632268800/1632355200

Untraceable

https://backpack.tf/profiles/76561198113093440#!/compare/1631923200/1632009600

https://backpack.tf/profiles/76561198049761080#!/compare/1632009600/1632096000

20 keys

https://backpack.tf/profiles/76561198110858518#!/compare/1632528000/1632614400

https://backpack.tf/profiles/76561198198105143#!/compare/1631750400/1633910400

Untraceable

https://backpack.tf/profiles/76561197972353065#!/compare/1633824000/1633910400

https://backpack.tf/profiles/76561198073278253#!/compare/1611964800/1634601600

Unsure if it's the 24 keys

https://backpack.tf/profiles/76561198263836417#!/compare/1631491200/1631577600

https://backpack.tf/profiles/76561198840565224#!/compare/1631232000/1631836800

19 keys

https://backpack.tf/profiles/76561198840565224#!/compare/1631836800/1632355200

https://backpack.tf/profiles/76561198204169516#!/compare/1632268800/1632355200

20 keys

https://backpack.tf/profiles/76561198204169516#!/compare/1634083200/1634169600

https://backpack.tf/profiles/76561198123789684#!/compare/1634083200/1634169600

Bulk

https://backpack.tf/profiles/76561198123789684#!/compare/1635724800/1635811200

https://backpack.tf/profiles/76561198993631639#!/compare/1635811200/1635897600

Bulk

https://backpack.tf/profiles/76561198993631639#!/compare/1635897600/1635984000

https://backpack.tf/profiles/76561199057379056#!/compare/1635897600/1636070400

Untraceable

https://backpack.tf/profiles/76561198850274253#!/compare/1635033600/1635120000

https://backpack.tf/profiles/76561198064658655#!/compare/1635033600/1635120000

https://gyazo.com/bbff6cbe06fdd5e4a821470c0186c534

18 keys 38 refined

https://backpack.tf/profiles/76561199107865875#!/compare/1630022400/1630108800

https://backpack.tf/profiles/76561198877934772#!/compare/1629417600/1630108800

Untraceable

https://backpack.tf/profiles/76561198877934772#!/compare/1631059200/1631145600

https://backpack.tf/profiles/76561198220098345#!/compare/1631059200/1631145600

Bulk

https://backpack.tf/profiles/76561198197047443#!/compare/1633392000/1635292800

https://backpack.tf/profiles/76561199084282838#!/compare/1632700800/1634947200

Untraceable

https://backpack.tf/profiles/76561199084282838#!/compare/1632700800/1634947200

https://backpack.tf/profiles/76561199017434769#!/compare/1630540800/1635379200

Untraceable

https://backpack.tf/profiles/76561198263836417#!/compare/1632268800/1632355200

https://backpack.tf/profiles/76561198064658655#!/compare/1632268800/1632355200

https://gyazo.com/b024771ae7dbcb637eac38babf49f69b

Bulk, but I apparently wrote it down as 19 keys

https://backpack.tf/profiles/76561198178611637#!/compare/1630627200/1636416000

https://backpack.tf/profiles/76561198064658655#!/compare/1635465600/1635552000

https://gyazo.com/0bb62ac8ae96d4f5feb1117721f4fe7c

15 keys to buy order

https://backpack.tf/profiles/76561198035925841#!/compare/1633305600/1633996800

https://backpack.tf/profiles/76561198263836417#!/compare/1633219200/1633305600

Untraceable

https://backpack.tf/profiles/76561198263836417#!/compare/1635465600/1635552000

https://backpack.tf/profiles/76561198064658655#!/compare/1635465600/1635552000

https://gyazo.com/ad652973aa57d4ce60603995ead93c78

18 keys

Sales

15 key buy order

17.5

18

19

19

19

20

20

21

21

21

22

22

22

Going with 18-22 keys