Haunted sniper sets sell quicker than any other haunted set (I've seen a couple go as high as 3 keys, sorry I couldn't provide links). People have offered 1 key, sometimes a little higher for H. holy hunter. I take my hat off to you if you bought it for 2.33 in the last month.

http://www.tf2outpost.com/trade/4040323 (bought supposedly for 3 ref)

http://www.tf2outpost.com/trade/3450231 (buying for 2.77, this trader probably knows their haunteds if you check the backpack)

http://www.tf2outpost.com/trade/4494076 (1 key offer)