This is a question we get asked all of the time regarding 3D printers, and it really depends on what you are looking to make. We recommend that people initially get started with a service bureau to 3D print their designs, typically the bureau will be able to cast your designs in your metal of choice as well. So for jewellers who do not do their own casting it is the easiest choice.
If you are designing pieces for a production range, typically with these type of designs a “master” is made, and then a mould is made to produce replicas in wax for casting in metal. The “master” can be printed in resin from an inexpensive 3D printer with resolution/quality less than 100 microns. That type of printer is approx $4,000 – $7,000 at current prices and there are some great offering using DLP (Digital Light Projector) technology like the B9 Creator and ASIGA machines. Unfortunately you can’t get away with a $1,500 3D printer, as the quality of the finish is definitely not suitable enough for jewelry sized objects.
If you are designing “one-off” pieces, like engagement rings, wedding rings, etc, then they are typically 3D printed in wax and direct-cast (lost wax cast). You need a 3D printer that can print in wax, you cannot use a resin-based 3D printer for reliable direct-casting in resin. The price for 3D printers suitable for printing in wax are still in the $25-30k ballpark as they are production-level printers aimed at people producing a minimum of 3-4 designs per day. The Kevox is one option, and we will happily arrange a print sample which you can cast to see the quality of finish.
So really to answer your question as to what type of 3D printer you need. If you are getting started with CAD, we would recommend using a 3rd party bureau to start with. There are plenty of them to choose from. Once you get some experience with the software, say 6-12 months from the start, you need to chose a 3D printer based on your work; one-off or a production range, and based on your weekly/monthly volume requirements. The good news is that the price of the technology is constantly being driven down with an increase on the number of manufacturers and obvious demand.