Bot.tf Stats:

https://bot.tf/stats/item?def=30252&q=6&ef=&craft=1&aus=0&ks=0&source=browser_script

https://i.imgur.com/XoIudC9.png

Nothing useful here, using marketplace sales, as suggested by Cashew.

https://marketplace.tf/items/tf2/30252;6 - Using the two September sales, everything else is over a month old.

Sold for $1.74 on the 5th of September

Sold for $1.69 on the 10th of September

http://manic.tf/keyprice?at=2019-09-05&price=1.74 - $1.74 / $1.81 = ~0.9613 keys

http://manic.tf/keyprice?at=2019-09-10&price=1.69 - $1.69 / $1.81 = ~0.9337 keys

https://bot.tf/stats/listings/Y7D183G9 - keys were selling for ~43.22 ref on the 5th

https://bot.tf/stats/listings/Y9G73E6X - keys were selling for ~44.22 ref on the 10th

0.9613*43.22 = ~41.54, rounding to 41.55

0.9337*44.22 = ~41.28, rounding to 41.33

https://i.imgur.com/8NlRIiD.png

Near-month-old seller at 1 key, bots selling for ~1.1 keys. Supports the drop.

Taking 41.33-41.55 ref.