http://www.tf2outpost.com/trade/19522319 seems like 1:1'd with a DP headsplitter 3.2 w/ overpay

http://www.tf2outpost.com/trade/19195885 sold it for a professional australium eye lander which he sold for

http://www.tf2outpost.com/trade/19229318 a battle scared stat-trak M4A4 (usually sells for 100 dollars) and a sf specialized bat

M4A4=2.1 earbuds and the sf specialized bat 1 bud so this sale is 3.1 but his b/o was 2.1 so this sale is 2.1 in reality

http://www.tf2outpost.com/trade/19258109 b/o's right here

http://www.tf2outpost.com/trade/19546049 oblivion bought his for a sf professional sniper rifle with fire horns and the cheapest firehorns on the community market is 138 dollars so divide that by 2.5 and its 55 keys so that sale is 2.8 earbuds

2.1 seems like a major outlier and there are 3 duped ones on the market and 2 clean ones