Has anyone done a business plan for worm composting?

I'm doing a project in one of my cles. I'm having trouble figuring out what the direct costs are for compost, worm casting, and worm tea . Most of the materials (as far a I can understand) are depreciated. Anyway, I would greatly appreciate your input. Furthermore, if you own a compost business I would like to know the general amount of startup costs (just to make sure I'm on the right track). Thanks.