Divide total cost by kilograms sold, after rejection, unsold lots and failed bags. That is the only cost that matters. A yield measured in Solan is not a sales figure in your block.
The downside is real. DMR reports competitor moulds taking up to 70 percent of an oyster yield. Unpacked paddy straw mushrooms lose 40 to 50 percent of their weight in four days. A buyer can refuse a lot.

