Well there's the cost of "making" your own brush, and the cost of "assembling" your own brush. To make one you need a lathe, the tools, grinder, jigs etc and that's a large chunk of change. To assemble one you just need a knot, a handle, and some epoxy. Money can be saved versus say a top of the line commercial brand name. Several members make them custom at very reasonable prices. For example, I purchased a block of wood and a knot, then had it made and assembled to my specifications.