The sellers selling for less has been going unnoticed. [Proof below]

Selling for less than current price

http://www.tf2outpost.com/trade/12613858

- Selling for 5 keys

http://www.tf2outpost.com/trade/12626194

- Selling for 5 keys

http://www.tf2outpost.com/trade/12618111

- Selling for 5 keys

http://www.tf2outpost.com/trade/12586796

- Selling for 4 keys + 1 refined

http://www.tf2outpost.com/trade/12597823

- Sold for 4 keys (quickly)

http://www.tf2outpost.com/trade/12602552

- Sold for 4 keys + 4 refined

Unsold at 5.5-6 keys

http://www.tf2outpost.com/trade/12298734

- Unsold for a week for 5 keys + 3 refined

http://www.tf2outpost.com/trade/12520770

- Unsold for 3 days for 6 keys

http://www.tf2outpost.com/trade/12463567

- Unsold for 5 days for 5 keys + 3 refined

http://www.tf2outpost.com/trade/12441737

- Unsold for 5 days for 5 keys + 3 refined

Unsold for ~1.4 keys

http://www.tf2outpost.com/trade/12513532

- Unsold for 3 days for 5 keys + 2 refined

http://www.tf2outpost.com/trade/12511222

- Unsold for 3 days for 5 keys + 2 refined

So let me know what you think, Trading Post isn't working for me so this is as much evidence as I can scrounge up.

Thanks!