The wood that has been cooked is smaller than its original size by about one-third. It must be broken down into marketable pieces. I have no reasonable cost estimate here - you've got to do a lot of leg work. Then you have to bag or package the carbon. Bagging machines are readily available from bagging equipment supply companies.
Charcoal presents somewhat of a bagging problem due to a large variance in sizes of the piece.
You can get less expensive ones. You might link up with a grill or outdoor oven company and combine your marketing efforts. Advertise the product as a superior, natural charcoal that has advantages over briquettes. Many people are not aware that charcoal is available in this all-natural form. A great publication on self-help suggestions for rural entrepreneurs is Income Opportunities in Special Forest Products.