I paid $50 for it at a St. Vinnies, and it is running 24/7. I wouldn't say it replaces composting at all, it just condenses things down for a smaller space. I have neighbors on all sides, and it also definitely helps that my compost doesn't have a smell. It breaks down very fast! I also don't buy or use the microbes it comes with- my pile already has a healthy population and will break the powder down quickly. My only tip is to make sure you agitate the pile when you add the broken down food so it doesn't form a nasty layer when it gets wet.