https://backpack.tf/profiles/76561198065601545#!/compare/1641168000/1641254400 - 17 Keys to a buy order

https://backpack.tf/profiles/76561199093293306#!/compare/1639958400/1640044800 - ?

https://backpack.tf/profiles/76561198850274253#!/compare/1639872000/1639958400 - Quicksold for 18 Keys + 2 Refined (Slobek has this on MP now)

https://backpack.tf/profiles/76561198025560677#!/compare/1639008000/1639094400 - ?

https://backpack.tf/profiles/76561198930899269#!/compare/1640476800/1640563200 - ?

https://backpack.tf/profiles/76561198108628484#!/compare/1640217600/1640304000 - ?

https://backpack.tf/profiles/76561199106931116#!/compare/1640995200/1641081600 - Only 10 Keys appear

https://backpack.tf/profiles/76561198039986078#!/compare/1639785600/1639872000 - 12 Keys + 16 Refined to a buy order?

https://backpack.tf/profiles/76561199106931116#!/compare/1640736000/1640822400 - 17 Keys appear

https://backpack.tf/profiles/76561197961976244#!/compare/1641513600/1641600000 - ?

https://backpack.tf/profiles/76561198023643621#!/compare/1642723200/1642809600 - Sold for 19 Keys + 33 Refined (<0.5 Keys at the time)

https://gladiator.tf/sales?item=Sublime%20Snowstorm%20Taunt:%20The%20Mannbulance!&at=2022-01-06T21:13:49.936Z - Multiple untraceable sales for less

With 2 sales at 18 Keys and multiple for less, it wouldn't make sense to eliminate them all, so a range of 18 - 19 would work here.