The amount of work required to turn garbage into compost is huge. very time consuming and labor intensive. Try your own compost heap first and then see what you think. Many people who have farm like acreage available to them abandon composting as all of animals come to eat, rats, raccoons, possums, whatever you have. And the odor from the decaying matter is most unpleasant, kind of like a garbage dump cause what it is.

And all nurseries sell bags of compost for low prices these days.

So, as you can see, I think a composting business is not advisable.