Some research on Outpost notes that 1 ref is possible for this item, and there are those unwilling to part with this item for just 0.66

http://www.tf2outpost.com/trade/11161089

An add for 1 refined.

http://www.tf2outpost.com/trade/11048438

-A 1 for 1 with a Strange Sniper rifle (1-1.33) offer

-Someone willing to trade some of the new hats for the Sydney Sleeper.

-2 hidden offers of 0.77

-One offer of 1 refined visible, another hidden

-Buyer willing to buy for posted price of 1 ref.

http://www.tf2outpost.com/trade/8926160

An offer of 0.66 open for 6 days... more than likely never sold.

http://www.tf2outpost.com/trade/11521810

Hidden offer of 0.88

http://www.tf2outpost.com/trade/11481062

Offer of 0.77

http://www.tf2outpost.com/trade/11331539

An add for 1.33... that is surprising. Also surprising is that 1 buyer offers 1 ref and another accepts for 1.33

http://www.tf2outpost.com/trade/8466733

Visible offer of 0.66-0.77, and one hidden offer of 1 ref.

http://www.tf2outpost.com/trade/10443655

Several offers of at least 0.66 are hidden.

http://www.tf2outpost.com/trade/11541861

One of the offers at 0.66 is hidden

http://www.tf2outpost.com/trade/4794797

Out of stock at 1 refined

http://www.tf2outpost.com/trade/11281439

Same person makes an offer of 1 ref, then 0.66... and he hid the 1 ref offer... dummy

http://www.tf2outpost.com/trade/11084866

2.33?

http://www.tf2outpost.com/trade/11057077

An add at 1 ref and one offer of 0.66 hidden

Although 0.66 offers are still popping up for this item, there are a lot of them that are being ignored.

All links I provided were those that were not part of a set or had any parts/tags on them.