Re-suggesting

Using last month

Sale 1:

Sold for 11 keys

Seller: https://backpack.tf/profiles/76561198170109470#!/compare/1522022400/1522800000

Buyer: https://backpack.tf/profiles/76561198162712360#!/compare/1522627200/1522713600

X = 11

Sale 2:

Bot.tf sale at 8 keys

https://i.imgur.com/DKHkJ4F.png

Couldn't find item history

X = 8

Sale 3:

Sold to a quickbuyer for 8 keys

Seller: https://backpack.tf/profiles/76561198049054413#!/compare/1524096000/1524182400

Buyer: https://backpack.tf/profiles/76561198048851745#!/compare/1524096000/1524182400

X = 8

Sale 4:

Sold for $14.1 on Marketplace.tf

https://marketplace.tf/items/1110;5;u3009

Can't find item's history

14.1/1.97 = ~7.16

X = 7

Sale 5:

Bulk for Frostbite VVF

Seller: https://backpack.tf/profiles/76561198054198170#!/compare/1524096000/1524182400

Buyer: https://backpack.tf/profiles/76561198049054413#!/compare/1524096000/1524182400

Sellers:

9 keys:

https://i.imgur.com/fKtzM6p.png

https://backpack.tf/item/5021758685

https://i.imgur.com/FZu1FXD.png

https://backpack.tf/item/2721991901

12 keys:

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

https://backpack.tf/item/6729526902

https://i.imgur.com/aVW81Fz.png

https://backpack.tf/item/3133397995

~13.9 keys:

https://i.imgur.com/EeFaiN2.png

https://backpack.tf/item/2690423447

20 keys:

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

https://backpack.tf/item/2882202544

49 keys:

https://i.imgur.com/mH5Bl1c.png

https://backpack.tf/item/4067347534

69 keys:

http://www.tf2outpost.com/trade/29579401

75 keys:

http://www.tf2outpost.com/trade/27764682

SCM: (only the first 5 are relevant to the suggestion)

https://i.imgur.com/vsxbuSx.png - taking keys as $2.47

$21.76 (~8.81 keys)

$21.78 (~8.82 keys)

$22.01 (~8.91 keys)

$22.21 (~8.99 keys)

$23.74 (~9.61 keys)

Sales at:

7

8 (2x)

11

https://i.imgur.com/V4Ox9sa.png - Quickbuyer at 8 keys, excluding 7 and 8

Several sellers at 9 (including SCM), using 9 as the low-end.

Going with 9-11.