Sale 1:

Sold with 2 keys for Max’s (~21)

Seller: https://backpack.tf/profiles/76561198101793900#!/compare/1551398400/1551744000

Buyer: https://backpack.tf/profiles/76561198317790700#!/compare/1551657600/1551744000

https://backpack.tf/item/6070971950

X = 19

Sale 2:

Sold with 3 keys for Max’s (~21)

Seller: https://backpack.tf/profiles/76561198080594357#!/compare/1552348800/1552435200

Buyer: https://backpack.tf/profiles/76561198877894851#!/compare/1552348800/1552435200

https://backpack.tf/item/6070971950

X = 18

Sale 3:

Sold for 15 keys

Seller: https://backpack.tf/profiles/76561198073435972#!/compare/1547078400/1551052800

Buyer: https://backpack.tf/profiles/76561198101793900#!/compare/1550966400/1551052800

https://backpack.tf/item/6070971950

X = 15

Sale 4:

Sold for 14 keys + cheap items

Seller: https://backpack.tf/profiles/76561198882972479#!/compare/1551830400/1552003200

Buyer: https://backpack.tf/profiles/76561198080594357#!/compare/1551916800/1552003200

https://backpack.tf/item/6070971950

X = 14

Other Sales:

https://backpack.tf/item/6070971950 (#1 & #2)

#1

Sold for Purple Confetti Snowcapped

https://backpack.tf/profiles/76561198317790700#!/compare/1551657600/1551744000

https://backpack.tf/profiles/76561198882972479#!/compare/1551571200/1551744000

Using on the fetti

#2

Sold for 4 unusual taunts

https://backpack.tf/profiles/76561198877894851#!/compare/1552608000/1552694400

https://backpack.tf/profiles/76561198106370774#!/compare/1552608000/1552694400

We have better sales to work with here, this may end up fitting in the range anyways.

Sellers:

https://i.imgur.com/SvA2KrW.png

https://backpack.tf/item/5311481084 - ~17.3 keys

Sales at:

14

15

18

19

https://i.imgur.com/tVhiLPu.png - Buyer at 14, excluding 14.

Going with 15-19.