What this hat makes me think of: http://i1.kym-cdn.com/photos/images/original/000/956/646/f43.png

Forgot overpay and the price range on the other suggestion... damn I'm tired.

Sale #1

Sold for a Dead Presidents Whoopee Cap (~21 keys)

before: http://backpack.tf/profiles/76561198095902384?time=1428735600

after: http://backpack.tf/profiles/76561198095902384?time=1428994800

With overpay, this sale values the Helmet at ~19 keys

Sale #2

Sold for a Kill-a-Watt Scotch Bonnet (~23 keys)

before: http://backpack.tf/profiles/76561198135586825?time=1427353200

after: http://backpack.tf/profiles/76561198135586825?time=1427439600

With overpay, this sale values the Helmet at ~21 keys

==Minis==

Whoopee Cap

Sold for a Cloud 9 Tough Guy's Toque (~24 keys)

before: http://backpack.tf/profiles/76561198146764497?time=1434178800

after: http://backpack.tf/profiles/76561198146764497?time=1434304028

Can't find any more clear, usable sales. Let me know if I missed anything.