d0's suggestion has really weak proof for its high-end

http://www.tf2outpost.com/trade/19854101 - sold for a max's + 1 bud + 1 key (rounding to 4)

http://www.tf2outpost.com/trade/20126411 - Phos Lucky Shot (~4*)

http://www.tf2outpost.com/trade/20111957 - KaW HWNN (~3) - outlier

http://www.tf2outpost.com/trade/21215165 - Miami Modest Pile of Hat, cannon offered on it. (no overpay - 6) - outlier

Sellers:

http://www.tf2outpost.com/trade/21303519 - 4

http://www.tf2outpost.com/trade/21252849 - 4

~~~~~~~~~~~~~~~~

*phos lucky mini:

http://www.tf2outpost.com/trade/21058993 - sold via Steam Market, was looking for 55 keys, ~3 buds (5 days) - outlier perhaps?

http://www.tf2outpost.com/trade/20849850 - quicksold for 3 buds

http://www.tf2outpost.com/trade/20900908 - sold for a DBD Tyrannus + minor sweets (~4)

http://backpack.tf/profiles/76561198042523095?time=1404198000 / http://backpack.tf/profiles/76561198042523095?time=1404284400