This needs a range.

Classified ads at time of posting:

http://backpack.tf/classifieds/?item=Knife&quality=11&tradable=1&craftable=1&australium=1

3*24 keys

1*2 buds

3*25 keys

Unsold at 25 keys:

http://www.tf2outpost.com/trade/25170243 (Has killstreak, 1 week, poorly bumped)

Sale at 25 keys (thanks to That Spu):

http://www.tf2outpost.com/trade/25185680#latest

Sellers at 24 keys:

http://www.tf2outpost.com/trade/25243909 (Has parts and is duped: http://backpack.tf/item/2860802160 , 2 days old)

http://www.tf2outpost.com/trade/25253323 (Has specialized killstreak and a spell, 1 day old)

Seller at 23 keys and 10 refined:

http://www.tf2outpost.com/trade/25233958 (2 days old)

This is all I could find on Outpost that are valid