Bro, this is for a rat, bro.

https://backpack.tf/item/461534234

Sale 1) ?

https://backpack.tf/profiles/76561198197769361#!/compare/1549756800/1549843200

Sale 2) Quicksold for 16 Keys

https://backpack.tf/profiles/76561198314211872#!/compare/1549756800/1549843200

https://backpack.tf/item/290210720

Sale 3) ?

https://backpack.tf/profiles/76561197999378162#!/compare/1547942400/1548115200

Sale 4) Sold for 16 Keys

https://backpack.tf/profiles/76561198314211872#!/compare/1548374400/1548460800

Sale 5) Bulk sale

https://backpack.tf/profiles/76561198307602421#!/compare/1549411200/1549497600

Sale 6) Sold for a Cloud 9 Bolted Bicorne + ~9 Keys of Items

https://backpack.tf/profiles/76561198119149660#!/compare/1549584000/1549670400

https://imgur.com/a/VoldOEP - Capped by the Buyout of 18 Keys

https://imgur.com/a/cJZiDBe - 2 Bicorne buyers over 8.5 Keys makes the sale round to 18 Keys even at buy order price.

Sale 7) Sold for 14 Keys to a buy order.

https://backpack.tf/profiles/76561198197609521#!/compare/1549584000/1549670400

https://backpack.tf/profiles/76561198447992809#!/compare/1549584000/1549670400

Low outlier.

Sale 8) Sold for 17 Keys

https://backpack.tf/profiles/76561198447992809#!/compare/1549670400/1549756800

Sale 9) Sold for 20 Keys

https://backpack.tf/profiles/76561198260201158#!/compare/1550534400/1550620800

https://marketplace.tf/items/108;5;u15 - Sold for $36.99 when Keys were ~$1.80 each and $38.46 when Keys were ~$1.80 each

https://marketplace.tf/items/5021;6/Mann%20Co.%20Supply%20Crate%20Key

36.99 / 1.8 = 20.55, which rounds to 21 Keys

38.46 / 1.8 = 21.36, which rounds to 21 Keys