Think about how much money you put into them for material cost, I know they are not the cheapest item to make. Think about the time you spend, I know they are easy but tedious.
When you think about it you may want to calculate something extra so it's worth it, now are the people ordering are willing what you ask for?
Usually here we think, well if they just pay me for the materials I used I'm fine. People who don't do crafts like us don't see how much is in it and usually don't appreciate it to the fullest.
What you make is custom made, not a product you find a dime and a dozen like in a store chain, neither is it made cheaply too.
I have seen them sold at a Bazaar for $50 D.
Enjoy all of your creations and be proud of it.