There had been a seller on Marketplace for a while at $500, which dropped to $450 two weeks ago and sold pretty much right away: https://marketplace.tf/items/30833;5;u14

There is also a very young seller now present at 250: http://www.tf2outpost.com/trade/29404276

I think generally speaking the flat value here is a bit higher than the hat's pure value with the $500 seller having been present for some time, but the sale it produced was immediate at ~230 and I would want to see stronger support for 230 before including it. Without a real midpoint value to create a range with, accepting as a conservative drop.