Sale 1:

Sold for Strange Shell Shocker Rocket Launcher (Field-Tested) (Mini at 9 below) + ~9 keys in items

http://www.tf2outpost.com/trade/28528020 - B/O of 16

Seller: http://backpack.tf/profiles/76561198021055079#!/compare/1475798400/1475884800

Buyer: http://backpack.tf/profiles/76561198113329444#!/compare/1475107200/1475971200

http://i.imgur.com/6iCn2HG.png

http://i.imgur.com/Tj1nIAS.jpg

http://i.imgur.com/om8k1uF.jpg

X = 16 (capped by B/O)

Sale 2:

Sold with 1 key in items for 16 keys

http://www.tf2outpost.com/trade/28465241 - No B/O

Seller: http://backpack.tf/profiles/76561198092570830#!/compare/1473033600/1473206400

Buyer: http://backpack.tf/profiles/76561198017223477#!/compare/1473120000/1473206400

X = 15

Sale 3:

Sold for 14 keys

http://www.tf2outpost.com/trade/28454988

Seller: http://backpack.tf/profiles/76561198023051867#!/compare/1472428800/1472515200

Buyer: http://backpack.tf/profiles/76561198092570830#!/compare/1472515200/1472601600

X = 14

Shell Shocker Mini:

http://steamcommunity.com/market/listings/440/Strange%20Specialized%20Killstreak%20Shell%20Shocker%20Rocket%20Launcher%20%28Field-Tested%29

Two recent sales at:

$23

$22.99

$23 average

23/2.49 = 9.2

After tax: $20

20/2.49 = 8

8-9.2 (8.6), rounding to 9

Sales at:

16

15

14

No current sellers

I quickbought it for 12 keys via my buy order

Going with 14-16