All those 5 key sales are within the current range, no need to change it. Warehouse also buys them for just under 4 keys and they have an ample supply.

Many of the 4keys b/o are grabbed, 5keys b/o are also selling. Managed to find two 4keys b/o unsold, new trades so going to see it progresses.

http://www.tf2outpost.com/trade/6929860 - 4keys b/o

http://www.tf2outpost.com/trade/6941166 - 4keys b/o

Edit: 2nd link sold, most probably first link will go quick when the guy is online