Selling 3D-printing files

There is a huge community around the 3d printing hobby nowadays, and this community has built massive databases of the files used with the machines in order to make things.  while a large portion of these files are free, there are also many instances of people selling their designs on marketplaces such as Printables or Etsy. Both of these platforms allow creators to upload files, set a price, and host a small web-store for a small monthly maintenance cost.  Granted, once you make a store, starting to make profit from sales is not easy, you often will need to advertise and otherwise promote your designs on social media or forums that focus on whatever niche your design is for.   you will also need to price it appropriately, as many people are not willing to spend a tonne of money on digital files.

Personally I am working on setting up a web store like this for foam dart blaster (nerf-esque) designs.  in order to do this, I have first made and tested the designs, then will research sources for the hardware needed to assemble the blaster, as well as optimize the files for personal use. I will then decide on an appropriate price per file-set, likely around six to ten dollars, and then post and promote it.   Another important detail is copywrite, as a 3d file is an intellectual property, these sites have built in systems to license your projects.