Sale 1:

Sold for 11 keys

No B/Os on Outpost

Seller: https://backpack.tf/profiles/76561198164651434#!/compare/1496361600/1496448000

Buyer: https://backpack.tf/profiles/76561198208909716#!/compare/1496361600/1496448000

X = 11

Sale 2:

Sold for $22 on Marketplace.tf

https://marketplace.tf/items/229;5;u35

https://backpack.tf/item/595197194

22/2.05 = ~10.7

X = 11

Sale 3:

Sold for $17 on Marketplace.tf

https://marketplace.tf/items/229;5;u35

https://backpack.tf/item/595197194

Seems pretty low, considering buyer(s) for $16. This’ll end up at around 8 keys here too.

Sale 4:

Bulk for Green Confetti Well-Wrapped Hat

Seller: https://backpack.tf/profiles/76561198031106685#!/compare/1494201600/1494806400

Buyer: https://backpack.tf/profiles/76561198069559160#!/compare/1494720000/1494806400

Sellers:

10 keys:

http://i.imgur.com/jeGsmdh.png - 22 days

Sales at:

11 (2x)

Aged seller at 10.

Going with 10-11.