Proof in comments

Sellers:

http://www.tf2outpost.com/trade/8216826 - 2 ref, unsold, 6 days

http://www.tf2outpost.com/trade/8228186 - 2 ref, undold, 6 days

http://www.tf2outpost.com/trade/8272994 - 2 ref, unsold, 4 days

http://www.tf2outpost.com/trade/8259172 - 2 ref, unsold, 4 days

http://www.tf2outpost.com/trade/8256334 - 2 ref, unsold, 4 days

http://www.tf2outpost.com/trade/8270994 - 2 ref, unsold, 4 days

http://www.tf2outpost.com/trade/8281220 - 2 ref, unsold, 3 days

http://www.tf2outpost.com/trade/8335968 - 2 ref, unsold,1 day

http://www.tf2outpost.com/trade/8327045 - 2 ref, unsold, 1 day

http://www.tf2outpost.com/trade/8274823 - 1.66 ref, unsold, 4 days

http://www.tf2outpost.com/trade/8313233 - 1.66 ref, unsold, 2 days

http://www.tf2outpost.com/trade/8357477 - 1.66 ref

http://www.tf2outpost.com/trade/8350031 - 1.66 ref

http://tf2tp.com/trade.php?trade=9093445 - 1.66 ref, sold

http://tf2tp.com/trade.php?trade=9091219 - 1.66 ref, sold

http://www.tf2outpost.com/trade/8176292 - 1.66 ref, sold

http://www.tf2outpost.com/trade/7673212 - 1.66 ref, sold

http://www.tf2outpost.com/trade/8267881 - accepted 1.44 ref offer

http://www.tf2outpost.com/trade/8360430 - 1.33 ref, 6 in stock

Buyers:

http://www.tf2outpost.com/trade/8318309 - 1-1.33 ref in weapons

http://www.tf2outpost.com/trade/7441586 - 1 ref

http://www.tf2outpost.com/trade/7805696 - 1 ref, according to the comments bought at least three in the last days

Also http://backpack.tf/classifieds/search/Strange%20Silver%20Botkiller%20Medi%20Gun%20Mk.II - 2 mediguns for 1.66 ref

Still possible to find a buyer at 1.66, but some sellers are willing to go lower down to 1.33 - 1.44

Quickbyuers are succesfully buying it for 1 ref.