How valuable are earthworm castings?

How Much Would You Pay for Value of an Earthworm and a Bee in Nature’s Bio-systems?

And when you don’t understand how webs connect; or how roots make leaves; or how the food web is many links that can’t be broken; when you lack empathy for the most ordinary creature, the worm or the bee, you become disconnected and pay the price one way of another, too often with disorder and disease.” Excerpt from Ecological Succession of