Price Bump...With the same range and updating it aswell with the proof see the link below for more info...

http://www.tf2outpost.com/trade/8150686 - 22 keys pure for Unusual

http://www.tf2outpost.com/trade/8285874 - 20 key,17 key in item

http://www.tf2outpost.com/trade/8317172 - Bmoc+mackrel(22 keys)

Conclusion - People likely looking for bud and getting offer around 20-22 keys pure and some in items and aswell the demand of the proof was less as there were of 3-4 trades there last price was set 4 months old.