Only one store in Varrock carries wizard hats. It is the Fancy Clothes Store in south-eastern Varrock, and is only available to members.
Go to varrock and go to the black wizard and you will find it. Or buy them at the Grand Exchange.
From other players. Or kill a wizard. Why not the Grand Exchange its fast and easy and if those are to hard sit in the Stronghold Security and wait for a shade to drop it. :)
the grand exchange in varrock
in the grand exchange in Varrock
varrock, above the west bank
You can buy buckets from general stores or from the grand exchange located in the north west corner of Varrock.
By teleporting for Varrock then walk to it from there, alternatively if you do most of the Varrock achievement diary tasks i think it's the 1st two parts, you don't have to do the hard ones just easy and medium, it will allow you to change the teleport location to Varrock grand exchange so that way you can just click teleport to varrock and it will take you to Grand Exchange instead of the Square.
easiest way is probably Grand Exchange in Varrock.
First, let me point out an alternative. Keep the Varrock teleport for Varrock center, and use the Ring of Wealth to teleport you to the Grand Exchange. If you really want the Varrock Teleport spell (this includes the house portal) to take you to the Grand Exchange, you must complete all the easy Varrock tasks, then talk to Rat Burgis. You'll find him next to a broken cart, south of Varrock.
Near the South Entrance of The Grand Exchange.
Silly question, at the Grand Exchange in Varrock.
The Grand Exchange, which is located North West of Varrock.