When looking at these links keep in mind there are only 2.1 pages of sellers to look through on outpost for this item and painted items can't be used as proof.

I did my best to get nearly all the available trades that are not troll trades.

Selling for 1.6 key (1 key 3.44 ref roughly)

http://www.tf2outpost.com/trade/12726383 Selling for whatever backpack says

http://www.tf2outpost.com/trade/12543039

http://www.tf2outpost.com/trade/12776182

Selling for 1 key 2 ref to 1 key 3 ref

http://www.tf2outpost.com/trade/12791683

http://www.tf2outpost.com/trade/12890184

http://www.tf2outpost.com/trade/12887160

http://www.tf2outpost.com/trade/12777957

http://www.tf2outpost.com/trade/12485168

http://www.tf2outpost.com/trade/12565905

Selling for 1 key 1 ref to 1 key 2 ref

http://www.tf2outpost.com/trade/12638373

http://www.tf2outpost.com/trade/12671087

http://www.tf2outpost.com/trade/12393366

http://www.tf2outpost.com/trade/12759372

Selling for 1 key and under

http://www.tf2outpost.com/trade/12771254

http://www.tf2outpost.com/trade/11796964

http://www.tf2outpost.com/trade/12794492

Classified

http://backpack.tf/classifieds/search/genuine%20battle%20bob

4 sellers at a key, 1 seller under a key and one seller at 1.6 keys

There are tons of sellers that are willing to sell this item below the current market value. However, near half of the listings I found (I tried to get as many as possible including the previous range) are available for 1key (or less)- 1 key 2 ref