Sale 1:

Sold for 18 keys

https://backpack.tf/profiles/76561198109986831#!/compare/1731888000/1732147200

https://backpack.tf/profiles/76561197967159739#!/compare/1732060800/1732147200

https://backpack.tf/item/14261561823

= 18 keys

Sale 2:

Sold for 17 keys + negligible metal

https://backpack.tf/profiles/76561199581722058#!/compare/1731456000/1731542400 - Near ID: 15136115923

https://backpack.tf/profiles/76561199081791855#!/compare/1731456000/1731542400

https://backpack.tf/item/13879499788

= 17 keys

Sale 3:

Sold for 15 keys + negligible metal

https://backpack.tf/profiles/76561198109879778#!/compare/1730419200/1730851200

https://backpack.tf/profiles/76561198310972287#!/compare/1730764800/1730851200

https://backpack.tf/item/15063690699

= 15 keys

Sale 4:

Sold to STN for 14 keys + negligible metal

https://backpack.tf/profiles/76561198139560938#!/compare/1730505600/1730592000

https://backpack.tf/profiles/76561199581722058#!/compare/1730505600/1730592000

https://backpack.tf/item/13879499788

= 14 keys

Sale 5:

Sold to a bot for 13 keys + negligible metal

https://backpack.tf/profiles/76561198023568099#!/compare/1728345600/1729728000

https://backpack.tf/profiles/76561199059160806#!/compare/1729641600/1729728000

https://backpack.tf/item/13879417055

= 13 keys

Other Sales:

#1

https://backpack.tf/profiles/76561197991733793#!/compare/1730505600/1730764800

https://backpack.tf/profiles/76561199742551901#!/compare/1730419200/1730505600

https://backpack.tf/item/15024506691

Untraceable

#2

https://backpack.tf/profiles/76561199742551901#!/compare/1730592000/1730678400

https://backpack.tf/profiles/76561198174890191#!/compare/1730592000/1730678400

https://backpack.tf/item/15024506691

Bulk for DBD Gauzed Gaze

#3

https://backpack.tf/profiles/76561198081175830#!/compare/1729641600/1729728000

https://backpack.tf/profiles/76561198109986831#!/compare/1729641600/1729728000

https://backpack.tf/item/14261561823

Bulk for DBD Le Party Phantom

Marketplace Sales:

https://marketplace.tf/items/tf2/31412;5;u3183

$39.99, November 19th

https://marketplace.tf/items/tf2/5021;6 - keys were $1.78

39.99/1.78 = 22.466, rounds to 22 keys.

Sellers:

https://i.imgur.com/TR5oUJv.png

https://backpack.tf/item/13879417055 - 20 keys

https://backpack.tf/item/14165038242 - 25 keys

Sales at:

13

14

15

17

18

22 (marketplace)

22 is a little bit of an outlier, is not a pure sale, and is higher than one of the sellers. Excluding 22.

A lone buyer at 15 keys, next highest are a bunch at 14. I will not exclude 15 with the lone buyer given the 3 sales at, or lower than, 15. I will exclude the sales lower than 15.

Taking 15-18 keys.