My first suggestion, thought the one by false friends (sorry for stealing your proof) should've been a range, so I am taking action.

Sold for 1.55: : http://www.tf2outpost.com/trade/24903895

Buyers (1.33):

http://www.tf2outpost.com/trade/24912298

http://www.tf2outpost.com/trade/25427798

http://www.tf2outpost.com/trade/24718163

http://bazaar.tf/trade/1244258

Sellers (1.33):

http://www.tf2outpost.com/trade/25403796

http://www.tf2outpost.com/trade/25320431 (specifies "backpack.tf prices", 1.33 at the time of the creation of the trade)

Unsold at higher prices:

http://www.tf2outpost.com/trade/25320431 (1.66)

http://www.tf2outpost.com/trade/25100242 (1.44)

While only 1 was sold my higher end, the market is quite small, (bazaar and op have only 1 page of buyers and sellers each), so I believe a rise in price is justified. Would really appreciate constructive feedback.