Garbage disposers range in price from just over $50 to nearly $300. What's the difference? The short answer is power, quietness and construction material. More expensive disposers can handle tougher jobs and tend to have more sound dampening insulation. There are two basic types of disposers: those that turn on and off with a wall switch and others that operate only when a tight-fitting cover is set in place. If you're on a septic system, you may want to consider an accessory that automatically injects enzymes each time the unit is operated.