The Candy Merchant's Hat costs 1,000,000 candies. It multiplies by 7 the number of candies found in a quest.
It is found on the Candy Merchant's head in The Shop in The Village.
"I could sell you my hat, but it is very precious, you know... You will have to give me a lot of candies for it. Let's say 1 million candies. It seems fair, right? "