There is 4 in existence so they a relatively rare.

Terror-watt is a good effect and relatively new.

I have had a look through backpack.tf and on average it looks like terror-watt is worth slightly more than killa-watt, so as the effect killa-watt on this hat is worth 1.7 terror-watt should be worth more around the 1.8 to the 2 bud mark. People on outpost are selling it for around this price and people have been buying.That is all the sale info i can find. sorry

There are some links to backpack.tf unusual prices that show terror watt is worth a bit more or the same as killa-wat

http://backpack.tf/unusuals/Bonk%20Boy

http://backpack.tf/unusuals/Hat%20With%20No%20Name

http://backpack.tf/unusuals/Your%20Worst%20Nightmare

http://backpack.tf/unusuals/Das%20Naggenvatcher

http://backpack.tf/unusuals/Cadaver%27s%20Cranium

to see the prices of terror-watt and killa-watt together on the page links i put at the bottem just type watt in the search bar at the top.

sorry if i havent done a good job this is my first try for pricing a item

clearly i have not done a good job with this i am going to remove it