The Sale:

Sold for 45 keys

Seller: https://backpack.tf/profiles/76561198115721685#!/compare/1601251200/1601337600

Buyer: https://backpack.tf/profiles/76561198046579190#!/compare/1601337600/1601424000

https://backpack.tf/item/1186103270

45 keys

Marketplace Sales:

https://marketplace.tf/items/tf2/605;5;u31

$79.99, July 1st

$99.99, September 13th

$99.99, September 22nd

http://manic.tf/keyprice?at=2020-07-01&price=79.99 - $79.99 / $2.02 = 39.60 keys

http://manic.tf/keyprice?at=2020-09-13&price=99.99 - $99.99 / $1.87 = 53.47 keys

http://manic.tf/keyprice?at=2020-09-22&price=99.99 - $99.99 / $1.87 = 53.47 keys

https://backpack.tf/item/894779895 - September 13th, no B/O

https://backpack.tf/item/3354936823 - September 22nd

https://bot.tf/stats/listings/46686K0L - B/O of 120

Couldn't find the remaining history.

After rounding, we have:

40 keys

53 keys (2x)

Other Sales:

https://backpack.tf/item/3354936823 (#1)

https://backpack.tf/item/1186103270 (#2)

#1

Bulk for Death at Dusk Pullover

https://backpack.tf/profiles/76561198099260958#!/compare/1596844800/1596931200

https://backpack.tf/profiles/76561198105071091#!/compare/1596844800/1596931200

#2

Bulk for Stormy Belt

https://backpack.tf/profiles/76561198090409013#!/compare/1597536000/1597622400

https://backpack.tf/profiles/76561198115721685#!/compare/1597536000/1597622400

Sales at:

40

45

53 (2x)

Taking 40-53.