If you are just getting into building stringed instruments, it’s a good idea to start with a small budget. By taking on a small project the beginner can learn a great deal about the physics of stringed instruments, build planning, and working with tools to achieve a desired result. All this said, I can’t think of an entry point to building stringed instruments that is more welcoming and forgiving than banjo making.
Keep the Cost Low and Learning Opportunity High
One of the most expensive parts of building a banjo is the hardware; tuners and rim hardware specifically. Tuners that do the job well are absolutely essential. Luckily, there are plenty of inexpensive options on the web. There are also good options for building a rim that do not rely on expensive hardware for holding tension on the head.
Use a Simplified Build Style
Keep your build style simple. A Hoop on Stick design for the neck / dowel stick can be achieved with a drill, a jigsaw, a rasp, a file, sand paper, a few screws, and some wood commonly found at many hardware stores or salvaged from old furniture.
Use Fixed Head Rim
Cookie tins, gourds, and cast off thrift store drums can all be used for building a banjo rim at low cost. While these options may sound lack luster, they can provide an inexpensive way to learn and grow in instrument building at low cost. A fixed head is a head that does not have hardware and cannot be adjusted. Gourd banjos and tack head banjos are good examples of this type of head.