well first of all any clean unusual can get 12 keys, and the last real update was 6 months ago, as the update 1 month ago was only showing that 12 keys was the lowest it should go, and not actually looking at sales for this hat

this hat is 1 of 1 on the market

http://www.tf2outpost.com/trade/11031348

c/o's

13-14 keys

white bills + 5 keys +1.2 keys in sweets - 16 keys

steaming madame dixie if seller adds sweets

http://www.tf2outpost.com/trade/8777359 - sold 15 keys 3 months ago

i cant find proof of the other sale

lowest c/o is 13 keys

highest c/o is 16 keys

sale is between that amount, so the range is 13-16 keys

edit:

http://www.tf2outpost.com/trade/6488987 - 19 keys 5 months ago( not going to count though, as 5 months is too old. 3 months also might be old as well)