Month 1: https://gladiator.tf/sales?item=Stunning%20Wild%20Brim%20Slouch&at=2022-06-14T11:47:00.748Z

Sales:

1 @ 10 keys

Buys:

1 @ 9 keys 10 ref ~9 keys

Month 2: https://gladiator.tf/sales?item=Stunning%20Wild%20Brim%20Slouch&at=2022-05-14T11:47:00.748Z

Buys:

1 @ 9 keys 30.88 ref ~9.5 keys

1 @ 9 keys 31.55 ref ~9.5 keys

1 @ 9 keys 31.66 ref ~9.5 keys

Month 3: https://gladiator.tf/sales?item=Stunning%20Wild%20Brim%20Slouch&at=2022-04-14T11:47:00.748Z

Sales:

2 @ 10 keys

Buys:

1 @ 9 keys 27.77 ref ~9.5 keys

1 @ 9 keys 30.22 ref ~9.5 keys

https://marketplace.tf/items/tf2/31192;5;u180

$22.99 / $1.75 = 13.14 keys ~13 keys

https://mannco.store/item/440-stunning-unusual-wild-brim-slouch

$14.22 / $1.60 = 8.89 keys ~9 keys

Sales at 9, 9, 9.5, 9.5, 9.5, 9.5, 9.5, 10, 10, 10, 13

https://gladiator.tf/time-machine?item=Stunning%20Wild%20Brim%20Slouch&at=2022-06-14T11:46:55.922Z

Sellers at 10 keys, buyers at just over 9

Calling 9 low and 13 high, going with 9.5-10 keys