Consider the market

Go into Armor, choose Leather, and click Head. Unclick Usable Items.

Consider the market. Someone at level 70 might not be willing to buy a level 72 hat yet, while a 74 would probably not buy Maple Story mesos. Try searching for 70-74 for wide parameters, or 71-73 for a tighter search.

When examining the other hats, do not just price match them. A hat with intellect and spell power might sell better than your intellect and agility piece! Know which stat combinations sell. This is not related to the Auction House, but rather to class and spec needs. If you are unsure, do some research or ask around.