It's a nice hat but really overrated.

Clean sales -

Sale 1 [estimated]:

http://www.tf2outpost.com/trade/24136747 - Sold for a a Steaming Chieftan's Challenge and 40-45 keys.

Note: It's impossible to track how many keys it actually was so I'll take the average which is ~43. I know it's not how it works but both are offline. It's likely that it was around 45.

1.1*0.9 = 1 bud

43/13 = ~3.3 buds.

Total: ~4.3 buds

Sale 2:

http://www.tf2outpost.com/trade/24175661 - Sold with a set. Added 9 keys for a Midnight Whirlwind Conga Taunt.

after - http://backpack.tf/profiles/76561198044128613?time=1420531200

before - http://backpack.tf/profiles/76561198044128613?time=1420444800

Items in the set [bp.tf prices] = ~76 ref.

76/13.16= ~5.8 keys.

Overpay on conga: 6.2 buds*0.9 = ~5.6 buds.

Total:

Value of the taunt: ~5.6 buds

Value of the keys + set items: ~1 bud.

5.6 buds - 1 bud = 4.6 buds.

That's all folks!