Proof below.

1 of 1 in world.

Sales:

http://www.tf2outpost.com/trade/15786955

-sold for ~43 keys=~2.3 buds

-seller's bp:

http://backpack.tf/id/76561198044913957?time=1384761600 harmburg+13 keys

http://backpack.tf/id/76561198044913957?time=1384934400 56 keys excluding new ones

http://www.tf2outpost.com/trade/15849105

-sold/bought for c9 western: http://www.tf2outpost.com/trade/15433041

-~2.6 buds

These are about all the traceable sales.

Current trade:

http://www.tf2outpost.com/trade/15887237

-necroted's trade, no offers

Very hard to find proof (sales and offers). About no offers at all and also 1 of 1, so just going by these 2 trades should be a fairly accurate range. This price is lower than p. fetti's so tier seems to be alright. Unusual overpay and original prices used when necessary.