Nut'N'Bolts Base Metal Billycock. Contrary to the stats, THREE of this in existance(One in the market, lvl 68 unrecorded in stats).

Despite it's rarity, gets traded around quite a bit. One Rec cut off to compensate item overpays.

Keys values at 6.22 for calculations.

1) http://www.tf2outpost.com/trade/15159481 Sold for 1 bud pure (19 keys mid range) - http://www.tf2outpost.com/trade/15898478 (Considered outlier, buyer was looking to buy any Base Metal for the bud)

2) http://www.tf2outpost.com/trade/15849619 Sold for 14 keys pure in 4 days time.

3) http://www.tf2outpost.com/trade/15884760 - http://i.imgur.com/Kx3ir2j.png (Screenshot provided by Enfrozt, many thanks.)

Sold for: S Original w/ parts (4 keys) + Gen. Doublecross-Comm TS (4 keys) + Gen Cross-Comm Express #216 Paint (1~ key) + Scotch Bonnet (2.66 ref) + Gib Kills part (1.66 ref) + Airborne Enemies Part (4.66 ref) + S Shotgun (1.5 keys) + S Degreaser w/ Pyros part (1.8 keys) + Unique Blood Banker (4.66) + Name Tag (2.33) + 10 ref pure = 16.4~ Keys.

4) http://www.tf2outpost.com/trade/15143936 Sold for a Stormy Dread Knot - http://www.tf2outpost.com/trade/15173216 (12 keys low end)

5) http://www.tf2outpost.com/trade/15429132 Sold for 12 keys pure.

Resulting range: 12-16 keys. Many thanks to Woifi for the help in calculating item overpay costs and the range.

Comment below if you see anything wrong or have any additional sales regarding the range, I'll try to correct it!

Edit: Whoops forgot another sale. Added it in.