Current price, 1.3 keys, is equivalent to 3.33 refined. It is demonstrably less than that.

http://www.tf2outpost.com/search/41166582- Quite a few uncraftable Marxman available, it's not an item short in supply by any means

Fully untaken trades, ranging from 2.33 to 3 ref

http://www.tf2outpost.com/trade/5231335

http://www.tf2outpost.com/trade/5285256

http://www.tf2outpost.com/trade/5278219

http://www.tf2outpost.com/trade/5270931

http://www.tf2outpost.com/trade/5279529

Several Marxmen sold over the past few days at 1 key,

http://www.tf2outpost.com/trade/5208566

http://www.tf2outpost.com/trade/5242052

http://www.tf2outpost.com/trade/5186322

http://www.tf2outpost.com/trade/5127454

Supplementary trades

http://www.tf2outpost.com/trade/5247753- One sold recently at 1.66

http://www.tf2outpost.com/trade/5276605- Asking for 2 ref, spoken for but yet untraded

http://www.tf2outpost.com/trade/5276653- Asking for Deus Ex- a 1 key item- spoken for but yet untraded and recently bumped

I put the 3 ref at a high point as I did see some offers of that quality on a couple trades over the past few days, 2.33 as a low point due to a trade still available at that point and a couple of trades that sold or were spoken for recently for even less.