Sorry, I don't wear any jewelry (besides my wedding ring!) and I have NO idea what your costs are or how long it takes you to assemble a piece.. That's something only you can decide, what it's worth.
You could take a look at similar items and see what they are priced at to be comparable but you might end up at a loss if they have ways to do it cheaper or faster.
I didn't want you to think we were ignoring you. Sorry, I couldn't be of more help.