Worm castings are great! I have a worm composting system (Can-O-Worms)in my garage - they produce about one 15 -lb tray of castings in about 8 weeks now, but when the garage temps get above 55 they'll give me about 15 lbs a month. The castings are better than normal compost or fertilizer because they provide both nutrients and soil amendment. They've never burned my plants, even in containers. I do give my container plants additional fertilizer. These worms are not the same as the ones that till your garden soil. Composting worms won't survive in your garden and normal earthworms from your garden won't survive in the composting system. Would I pay $10? I don't know - like regular compost, it sort of makes more sense to produce it yourself. There are self-contained systems on the market that are clean & small & don't smell for about $100, or you can make your own. In many zones they can be kept outside in a shady area or in a garage or basement. I have url's for worm composting discussion boards, sites, etc. . . email privately if you want them. -shan shannolater@alumni.williams.edu