EDIT, for context: User robertlangdon originally included the same typeform.com link in every comment, but has now edited most of the comments to remove these links.

For a prototype which is expected to drive some interest 3d printing is fine, but print at 0.15 layers and do a couple of runs of sanding combined with filler before applying some paint. The case will look just like a regular finished product. I do this for custom projects where I want a perfect finish and/or show-off prototypes.

The layering is really annoying for some people.

For a final product, depending on the sale numbers, injection molding might be the only option. SLS and MJF give a very nice result, but the price range where they're economically viable is very narrow.

If you search for something along the lines of "paint and sand 3d print" or "finish 3d print" you'll find lots of different articles.

Edit: $59 mentioned lower in the thread.