Counter Suggestion, this time with actual research.

Sold for Peace Sign Chapeau (~1.8)

http://www.tf2outpost.com/trade/20374633 (Beret)

http://www.tf2outpost.com/trade/20314709 (Chapeau)

Sold for Blizzardy Storm Voodoo Juju (~1.7 but 4 month old price)

http://www.tf2outpost.com/trade/20189123 (Beret)

http://www.tf2outpost.com/trade/20051191 (Juju)

Offered on (and sold for) a Kill-a-Watt Vintage Merryweather (~2.1) + 9 keys = ~1.6

http://www.tf2outpost.com/trade/20093129 (They complain about duping but for an item of this value and rarity its irrelevant)

Sold alongside a S.F Sticky (~1 bud) for a Haunted Ghosts German Gonzilla (~2) = ~1 for Beret

http://www.tf2outpost.com/trade/19871527

http://backpack.tf/profiles/76561198043799932?time=1401951600 (Sweets are minor, only ~2 keys if being generous)

Above sale matches a successful(?) quicksale price (1 bud + 4 keys) therefore definite outlier

http://www.tf2outpost.com/trade/20938210