Team Fortress 2
Counter-Strike: Global Offensive
Still need this one for my collection and missed my chance q.q
Second try. Thanks to human and Kλito for a new sale.
https://marketplace.tf/items/tf2/15000;15;u704;w5;pk14;kt-1 - Two recent sales, no marketplace hits on any other killstreak variant.
$24 - keys at $1.81 -> 13.26 keys, rounds to holy mother of quicksells!
$149.99 - keys at $1.80 -> 83.33 keys, but buyout capped at 75 keys.
Screenshot of listing for buyout - https://i.imgur.com/nnQhGUt.png
Another sale happened in between the two marketplace sales.
https://i.imgur.com/Jk7EL8K.png -> Sold for 50 keys.
Item history (currently unupdated) - https://backpack.tf/item/4084725898
Two more of these seem to exist, both Pro KS, but I do not know if they have sales due to lacking premium. I can only confirm that they did not sell on marketplace.tf.
Now of course, the definition of a 'quicksell' is going to come into question here as all of these sales happened within roughly a day.
Given buyers, the first sale gets dropped. However, given those same buyers I don't see an obvious reason to leave out either of the other sales as outliers, leaving us with a range of 50-75 keys.