(Resuggestion due to errors I made in the previous one.)

Strange Geometrical Teams War Paint (Factory New)

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

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

2 sold on March 15th, 2020:

$27.36/$2.16 = 12.67 ~ 12.7 keys

1 sold on March 28th:

$38.27/$2.12 = 18.05 ~ 18 keys

https://marketplace.tf/items/tf2/17215;11;w1;pk215

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

1 sold on January 28th:

$16.67/$1.78 = 9.36 ~ 9.4 keys

1 sold on February 16th:

$22.25/$1.77 = 12.57 ~12.6 keys

2 sold on February 26th:

$18/$1.77 = 10.17 ~ 10.2 keys

$15.51/$1.77 = 8.76 ~ 8.8 keys

Outliers: 8.8 keys, 9.4 keys, and 18 keys.

Taking 10.2 - 12.7 keys as the range.