Yes, these are expensive! The reason is that each one is mounted on a plastic backing machined to fit your Mini Grinder. So listen to Pop again: Don't throw these out after the sanding surface becomes worn! Simply purchase some standard 2" sanding discs and glue them on top of the existing disc. I will glue 3 or 4 discs on top of each other on my Mini Grinder before scraping them all off and starting over. The ONLY time you should consider purchasing a package of these discs is when you have worn out the plastic mounts. And remember ..a soft touch during use is the secret to long disc life!