Redoing this suggestion because I screwed up the formatting on the last attempt and it was really bugging me, also just got premium again so I can make sure no other sales happened in the 6 days between the previous accepted suggestion and mine. Credits to Explocivo808 for the previous suggestion.

https://backpack.tf/suggestion/64caa8139b11cf44a50b1066

https://marketplace.tf/items/tf2/1106;5;u3014

MP.TF Sale #1

Unknown history

Sold for $69.99 on May 18, 2023

Keys @ $2.02

69.99/2.02 = 34.65ish keys

MP.TF Sale #2

Unknown history

Sold for $40 on July 26, 2023

Keys @ $1.95

40/1.95 = 20.51ish keys

MP.TF Sale #3

https://backpack.tf/item/3077202749

Sold for $50 on August 8th, 2023

Keys @ $2.04

50/2.04 = 24.51ish keys

Sales @ 21, 35, 25

With a new sale right in the middle of the other 2 previous sales, makes sense to include the higher on now. Taking 21-35 keys.