While looking for proof on purple energy I noticed this one deserves a bit of an update as well. Again not much proof but i will list as much as i can.

3 on market right now, http://www.tf2outpost.com/trade/10944890 b/o overpriced 10 buds, but he got a 8 bud offer before - http://www.tf2outpost.com/trade/10792190 by Kobb.

http://www.tf2outpost.com/trade/11192353 c/os of Ghost Beak- 6.2 + 1 bud, 8.5 collecting (?), and a few more around this price range

http://www.tf2outpost.com/trade/11426895, c/os of around 7 buds in mixed, and a p.e. charmers (This guy doesnt bump his trades a lot it seems)