(Resuggestion)

Strange Star Crossed War Paint (Factory New)

https://steamcommunity.com/market/listings/440/Strange%20Star%20Crossed%20War%20Paint%20%28Factory%20New%29

Dividing by the average price of a key on that day.

1 sold on January 4th, 2020:

$39.27/$2.48 = 15.83 ~ 15.8 keys

1 sold on January 30th:

$38.26/$2.41 = 15.87 ~ 15.9 keys

1 sold on January 31st:

$52.11/$2.41 = 21.62 ~ 21.6 keys

1 sold on March 27th:

$21.57/$2.18 = 9.89 ~ 10 keys

https://marketplace.tf/items/tf2/17208;11;w1;pk208

Dividing by the average price of a key on that day.

1 sold on January 14th:

$28.45/$1.77 = 16.07 ~ 16.1 keys

1 sold on January 31st:

$24.99/$1.76 = 14.19 ~ 14.2 keys

Outliers: 21.6 keys and 10 keys.

Taking 14.2 - 16.1 keys as the range.