I have spent a lot of time researching 3d printers for a solution to make chocolate molds. A 3d printer would be ideal as you do not have to know how to use CAM software or generate toolpaths as you do with CNC machine. Just design in 3d modeling software and print.
To date, I am yet to find an acceptable 3d printing solution that is affordable. There are certain machines that are capable of very high quality fine printing, but they cost over $150,000. The lower priced machines are good for making larger models with larger text.
First, most 3d printers use only certain types of materials that are not food grade. It may be the type of plastics that are used or the adhesive functions used to build the layers that are not certified for contact with food. So, while it may be fine for your individual use or display purposes, this would not be acceptable for use in food or molds you are selling.
Second, 3d printers are best suited for larger items and cannot get the best detail for text in a small format. I once tested this on a Dimension 3d printer which makes parts by basically melting a thin plastic rod (looks like the weed whacker spool) and then depositing it. I wanted to make a standard size bonbon with small text on it. While it was fine to make to the base of the chocolate, the text did not come out. It was just a blob of illegible melted plastic. I did see the ZCorp 3d printer produce small text. But the ZCorp machine uses non-food grade materials and has a very rough surface. That process is of depositing a thin layer of a plaster or starch type substance, then adhering between layers.
Third, the surface finish on a 3d printed part is still quit rough no matter which you are looking at, unless you get into these very expensive printers. Even with sanding, it's not going to have a good enough surface to produce a smooth chocolate. Chocolate will pick up very fine detail in a mold. It will not have the proper luster.
That being said, I know they are making huge advancements in the 3d printing world daily and I continue to seek for a solution.