All trading bots on stes like TF2outpost.com or bazaar.tf have raised their lower key buying prices to above the maximum value here. Please note that these bots are tools for making a profit as quickly as possible, so appearently they couldn't buy keys anymore when they asked for the "official" backpack.tf price. This alone is reason enough for me to ask for a price raise. Here is some proof:

http://www.tf2outpost.com/trade/24255488 (buying for 16.77 ref per key)

http://www.tf2outpost.com/trade/20867153 (buying for 17 ref per key)

http://www.tf2outpost.com/trade/21521961 (buying keys for 17 ref per key)

http://www.tf2outpost.com/trade/23903641 (buying keys for 17 ref per key)

http://www.tf2outpost.com/trade/24305218 (buying keys for 18 ref per key)

http://www.tf2outpost.com/trade/24055156 (buying keys for 16.33 ref per key)

http://www.tf2outpost.com/trade/23873335 (buying keys for 17 ref per key)

I can add more proof if anybody asks, but if you are really doubting me, just go on tf2outpost, then go to search, and put a key in the left window and a refined in the right window, then search. All results will be selling/buying keys for more than the price on this site.