Using last month.

Sales 1 & 2:

Sold for $14.79 and $10 on marketplace.tf

https://marketplace.tf/items/30876;5;u3007

14.79/1.97 = ~7.51

10/1.97 = ~5.08

X = 7.5

X = 5

Sale 3:

Sold for 7 keys

Seller: https://backpack.tf/profiles/76561198061275415#!/compare/1524182400/1524268800

Buyer: https://backpack.tf/profiles/76561198049781697#!/compare/1524096000/1524528000

X = 7

Sale 4:

Sold for Whirlwind Yeti Punch (6)

No outpost

Seller: https://backpack.tf/profiles/76561198097271466#!/compare/1524873600/1524960000

Buyer: https://backpack.tf/profiles/76561198302639513#!/compare/1524873600/1525046400

X = 6

Sale 5:

Sold with ~1.25 keys in metal/items for Australium Blutsauger (~6.25)

No outpost

Seller: https://backpack.tf/profiles/76561198302639513#!/compare/1525651200/1525737600

Buyer: https://backpack.tf/profiles/76561198061275415#!/compare/1525651200/1525737600

X = 5

Sellers:

~5.7 keys:

https://i.imgur.com/J2xAGrX.png

https://backpack.tf/item/6479632502

https://i.imgur.com/yd9pRIN.png

https://backpack.tf/item/6266705740

14 keys:

https://i.imgur.com/L5Ojym8.png

https://backpack.tf/item/6252906745

Sales at:

5 (2x)

6

7

7.5

Don’t wanna stray too high above the sellers. Will include the pure sale at 7, but exclude the marketplace sale at 7.5.

Going with 5-7.