Sale 1:

Sold for 25 keys

Seller: https://backpack.tf/profiles/76561198000646505#!/compare/1517788800/1517875200

Buyer: https://backpack.tf/profiles/76561198105935327#!/compare/1517702400/1517875200

X = 25

Sale 2:

Sold for 25 keys

Seller: https://backpack.tf/profiles/76561198309332284#!/compare/1519948800/1520035200

Buyer: https://backpack.tf/profiles/76561198382379121#!/compare/1519948800/1520035200

X = 25

Sale 3:

Sold for $39 on Marketplace.tf

https://marketplace.tf/items/30964;5;u62

https://backpack.tf/item/6699651252

39/1.97 = ~19.8

X = 20

Sale 4:

Bulk for Scorching Polar Bear

Seller: https://backpack.tf/profiles/76561198072811851#!/compare/1521936000/1522368000

Buyer: https://backpack.tf/profiles/76561198125791160#!/compare/1522281600/1522368000

Sale 5:

Bulk for Burning Flames Hot Dogger

Seller: https://backpack.tf/profiles/76561198204285311#!/compare/1523491200/1523577600

Buyer: https://backpack.tf/profiles/76561198344429943#!/compare/1523404800/1523577600

Sale 6:

Sold for Aces High Ninja Hood

Seller: https://backpack.tf/profiles/76561198344429943#!/compare/1523577600/1523664000

Buyer: https://backpack.tf/profiles/76561197964171516#!/compare/1523577600/1523664000

Can be used on the Hood, we have plenty of pure sales to work with here.

Sale 7:

Untraceable sale, only 16 keys match, had a B/O of 25 keys so i doubt it would've sold for that much less

http://www.tf2outpost.com/trade/29587735

https://backpack.tf/profiles/76561198073553007#!/compare/1521072000/1521158400

https://backpack.tf/profiles/76561198072811851#!/compare/1520812800/1521158400

Sellers:

25 keys:

https://i.imgur.com/L1yD6sD.png

https://backpack.tf/item/6549275597

Sales at:

20

25 (2x)

Going with 20-25.