The classifieds tell all.

Classifieds:

http://i.imgur.com/8wytTOi.jpg two at 1.4, two at 1.5, one at 1.8, four at 2 keys

and for future reference: http://backpack.tf/classifieds/search/307/3/0

Unsold at 2 keys

http://www.tf2outpost.com/trade/12577756 1 week

http://www.tf2outpost.com/trade/12628281 1 week

http://www.tf2outpost.com/trade/12818745 6 days

http://www.tf2outpost.com/trade/11407204 1 month

http://www.tf2outpost.com/trade/12504783 2 weeks

http://www.tf2outpost.com/trade/12928208 3 days (trolls much?)

http://www.tf2outpost.com/trade/11724816 1 month

http://www.tf2outpost.com/trade/12648675 1 week

http://www.tf2outpost.com/trade/12974841 1 day

http://www.tf2outpost.com/trade/12970660 2 days

http://www.tf2outpost.com/trade/12916131 3 days

http://www.tf2outpost.com/trade/12252583 3 weeks

http://www.tf2outpost.com/trade/12353248 2 weeks

Unsold at ~1.8 and below

http://www.tf2outpost.com/trade/12925292 ~1.8

http://www.tf2outpost.com/trade/11032935 ~1.7

http://www.tf2outpost.com/trade/12904282 ~1.7

http://www.tf2outpost.com/trade/12966301 ~1.7

http://www.tf2outpost.com/trade/12884917 ~1.7 (Black paint)

http://www.tf2outpost.com/trade/13008683 ~1.5

http://www.tf2outpost.com/trade/13016923 ~1.5 (Unsuccessful sale so closed)

http://www.tf2outpost.com/trade/12804343 ~1.4

Sold at ~1.8 and below

http://www.tf2outpost.com/trade/12854527 ~1.7 (Seems to be a success, no longer in his bp and he was the one selling for 1.8 in the sceenshot of the classies I had)

http://www.tf2outpost.com/trade/12975662 ~1.2 (Quicksell)

Hard to find any sales, but this item is deserving of a drop to 1.4-1.8 keys because of the lack of any sales above 1.8 and the amount of people willing to sell below 1.8.

Any additional proof helps.