I make embroidered monograms for bridal gowns and charge $15 for either a monogram or wedding date. I charge $20 if they want both on the label. That being the case, I would discount if there were multiple labels of the same. I think $10 each is a fair price for your time, materials, expertise, and cost of owning and running your machine. Good luck. Some people really have no idea what is involved in this kind of custom product.