Sale 1:

Sold for 10 keys (ref wasn’t involved.)

Seller: https://backpack.tf/profiles/76561198011321852#!/compare/1495670400/1495756800

Buyer: https://backpack.tf/profiles/76561198272955027#!/compare/1495670400/1495756800

X = 10

Sale 2:

Bulk

Seller: https://backpack.tf/profiles/76561198355319852#!/compare/1497571200/1497744000

Buyer: https://backpack.tf/profiles/76561198213623463#!/compare/1497225600/1497744000

Sale 3:

Sold to a bot

Seller: https://backpack.tf/profiles/76561198272955027#!/compare/1496016000/1496102400

Buyer: https://backpack.tf/profiles/76561198304138933#!/compare/1495929600/1496016000

Couldn’t identify how much it went for, but given the current sell listing, it would most likely be less than that.

Sellers:

9.27 keys:

http://i.imgur.com/tzXEP9R.png - 7 days, definitely re-listed

https://backpack.tf/item/2857637201

Sales at:

10

Can’t ignore the seller at less than 9.5 keys, despite the buyers for more than 9 keys.

Going with 9-10.