This definitely needs a bump down. Higher end remains at 5 keys due to 1 sold at that price as well as 1 offer of 5 keys. Proof below:

Selling for 4 keys:

http://www.tf2outpost.com/trade/9550222

Accepted 4 keys:

http://www.tf2outpost.com/trade/9404722

http://www.tf2outpost.com/trade/9505266 (sold)

Being offered 5 keys:

http://www.tf2outpost.com/trade/9404117

Selling for 5 keys:

http://www.tf2outpost.com/trade/9570338 (being offered 4 keys)

http://www.tf2outpost.com/trade/9513766 (2 days)

http://www.tf2outpost.com/trade/9522220 (2 days)

http://www.tf2outpost.com/trade/9487622 (inactive)

Sold for 5 keys:

http://www.tf2outpost.com/trade/9481017

Painted green, looking for around 5 keys:

http://www.tf2outpost.com/trade/9460218 (inactive)

Selling a lime one for 5 key 1 ref:

http://www.tf2outpost.com/trade/9254141 (1 week, not sold)

Selling a team spirit one for 5 keys 2 ref:

http://www.tf2outpost.com/trade/9484903 (no offers)