Only 4 sellers on outpost and all are well out of the current range. Behold:

SELLERS

http://www.tf2outpost.com/trade/8814467 - 2.33ref offer

http://www.tf2outpost.com/trade/6239808 - selling successfully at 2

http://www.tf2outpost.com/trade/7034307 - many interested buyers, but out of stock at 3 ref

http://www.tf2outpost.com/trade/8389161 - selling unsuccessfully at 3, but offers at 1.44 - 1.77

BUYERS

http://www.tf2outpost.com/trade/8225203 - buying successfully? at 1.33

http://www.tf2outpost.com/trade/8487482 - buying successfully at 1.55

http://www.tf2outpost.com/trade/8505383 - buying unsuccessfully at 1.33

0 on backpack.tf classifieds.

http://steamcommunity.com/market/listings/440/Mann%20Co.%20Supply%20Crate?filter=21 $2.00+ on Steam Market

I have also had an easy time selling these crates at 2 ref. http://www.tf2outpost.com/trade/8369648

I feel the range could easily be 1.33 - 2 ref, but I'm being cautious here and only giving a small price bump.

Side note: It's an absolute pain finding buyers for crates on outpost because you can't limit your search to specific series :(