1 key was too low, personally, I downvoted. I suppose there should be a range as for now.

Solds at 1 key:

http://www.tf2outpost.com/trade/19137494

http://www.tf2outpost.com/trade/19130495

http://www.tf2outpost.com/trade/19114745

http://www.tf2outpost.com/trade/19114338

http://www.tf2outpost.com/trade/19034736

http://www.trade.tf/trade/532279734

Sold at 1.4 keys:

http://www.tf2outpost.com/trade/19088404

Solds at 2 keys:

http://www.tf2outpost.com/trade/19143914

http://www.tf2outpost.com/trade/19148627

http://www.trade.tf/trade/532163569

http://bazaar.tf/trade/760729 - 2.4 keys sold (not in bp)

Current sellers (trades to watch):

http://www.tf2outpost.com/trade/19100473 - 1 key

http://www.tf2outpost.com/trade/19041879 - 1.4 keys

http://www.tf2outpost.com/trade/19135087 - 2 keys

http://www.tf2outpost.com/trade/19036566 - 2 keys

http://www.tf2outpost.com/trade/19036566 - 2 keys

http://www.tf2outpost.com/trade/19150173 - 2 keys 6 ref

http://www.tf2outpost.com/trade/19155017 - 3 keys (painted)

And that's it - half page on OP, really small market.

As far as all the chemistry sets have the same cost to produce a strangifier, it costs about a key to make strange juggernaut jacket. 3 ref + 3 stranges (0.33 each cos we don't have scrap stranges anymore due to these chemistry sets) + 3 ref the cost of the unique jacket = 7 ref.