http://backpack.tf/profiles/76561198024567946?time=1394006400 and [url]http://backpack.tf/profiles/76561198024567946?time=1394092800[/url]: Sold for 25 keys. The sale occured in this trade: http://www.tf2outpost.com/trade/18217443

This trade occured literally 2 months ago today, so technically, it would not be considered valid proof, but, as is stated in the Unusual price suggestion guide in the forums:

"For very rare hats, if there have only been 1-2 sales in the last 3 months, a trade up to 3 months old is okay to use as proof to establish more data points. Keep in mind, new sales should take precedence over older ones." ~blind polar bear

No other sales or open trades (aside from one extreme highballer) in the past 3 months, so I'd say we're good here.