Take into count that the hat is 1 of 1 in the world, so you won't meet that many trades here.

Previous suggestor lacked evidence, and finally i took my lazy ass to fix this.

First trade made - me buying this hat.

[url]http://puu.sh/3BK0u[/url]

The previous suggestor missed the Smoking Pyromancer's from the count, which probably was sold through a trade server or presented to a friend, so there was no trade on outpost.

[url]http://backpack.tf/id/76561198045034691?time=1370070000[/url] - here's my bp before the date of the trade, where you can see me owning a bunch of Smoking hats (pages 11-13)

[url]http://backpack.tf/id/76561198045034691?time=1370242800[/url] - my bp after with a power surge tree and without 5 smoking hats, depicted on the screenshot of trading history.

By that day's value of buds and the price of hats involved i paid about 4.5 buds (that's the pure price, including overpay)

[url]http://www.tf2outpost.com/trade/11659049[/url] - the following trade has the offers which previous sugesstor refused to add in the range. I consider the offers should be included in the range, since they represent what people are willing to pay for the hat. I think the previous suggestion got accepted just because it was the first one on this hat.

So the offers are:

Circling heart Rather Festive Tree + 15 keys [~4.4 buds]

Nuts'n'Bolts Brainiac Hairpiece lvl 69 [5+ buds]

5 buds pure

These offers include overpay

I didn't take to the count robo hat offers, because it's quite hard to check their value (most of them have even more offers of robo hats and this chain can go really far).

Sold for Cloudy Moon Jeepcap [4.3+ buds]

[url]http://puu.sh/3FOkB.png[/url] - proof of the trade, you can see the jeepcap in my bp.

Some post scriptum: If you wonder why i didn't take the 5 pure or brainac, well that's simple, i was on a mountain trip for a week and had niether internet nor electricity, and when i returned, all of them got retracted already. Why i sold for the jeepcap? Well currently i'm aimed on another hat, so i took the first decent offer. Still 5 buds can be reached, since the offers are not too old.

On the basis of the proof above i consider the value should be updated and should take the range 4.3-5.