I suggest 1.66 flat, as long as on the market you can't find a 1.33 seller and even if you find it, the hat goes away very fast.

Sellers/Sold

http://bazaar.tf/trade/542972 (1.55 ref)

http://www.tf2outpost.com/trade/15702404 (1.55 ref)

http://www.tf2outpost.com/trade/15700799 (1.66 ref)

http://www.tf2outpost.com/trade/15599049 (1.66 ref)

http://www.tf2outpost.com/trade/15746179 (1.66 ref)

http://www.tf2outpost.com/trade/15707386 (1.66 ref)

http://www.tf2outpost.com/trade/15703019 (1.66 ref)

http://www.tf2outpost.com/trade/15727468 (1.66 ref)

http://www.tf2outpost.com/trade/15734824 (1,66 ref)

http://www.tf2outpost.com/trade/15706120 (1.66 ref)

http://www.tf2outpost.com/trade/15555294 (1.66 ref)

http://www.tf2outpost.com/trade/15571365 (1.66 ref)

http://www.tf2outpost.com/trade/15692625 (1.66 ref)

http://www.tf2outpost.com/trade/15804237 (1.66 ref)

http://www.tf2outpost.com/trade/15807027 (1.66 ref)

http://www.tf2outpost.com/trade/15740042 (1.66 ref)

http://www.tf2outpost.com/trade/15720853 (1.66 ref)

http://www.tf2outpost.com/trade/15805097 (1.66 ref)

http://www.tf2outpost.com/trade/15717034 (1.66 ref)

http://www.tf2outpost.com/trade/15537234 (1,66 ref)

http://www.tf2outpost.com/trade/15707386 (1.66 ref)

http://www.tf2outpost.com/trade/15717463 (2 ref)

http://www.tf2outpost.com/trade/15709479 (2 ref)

http://tf2tp.com/trade.php?trade=9899913 (2 ref)

Conclusion:

Most of the trades happen at 1.66, even trade.tf median price is 1.66 refined metals. Trades with 2 Refined Metals happen sometimes, but in a very slow way to be considered in a range. Trades at 1.33 refined metals happen very fast (I have few proofs of this thing).

Feel free to support/counter my proofs