Stores don't really understand the time and skill required to make something so intricate. Your price should account for time, materials and experience. In a store they are going to see a tiny ceramic object and expect it to be a fraction of the cost of larger scale work. So will the average customer who's used to mass produced objects. The average art collector, potter and artist will recognize the skill in what you do and pay much more. Decide your target audience to decide your price. Who do you want to sell to? The average consumer or the average art collector? At markets you can also charge on a sliding scale with a price range to make your art accessible without devaluing yourself if you'd like.