The picture below shows 1 lb of dried ginseng leaves, they are not packed in the bags so hard as to crush the leaves only lifted by the handles lowered onto a surface to let gravity pack them. This is only the tops and not the entire stem.
Whenever i top my ginseng,i will use the same type of bags to collect it in.
After spending a few days in the woods topping ginseng boredom sets in and you will eventually come across the idea to count how many plants will fit into the bag. Yes as sad as it sounds i have counted the plants multiple times to figure out how many plants fit into the bag. So the average number of plants is around 2000, these are without most of their stem. Now after i dry the leaves, the mass changes and it then takes at least 2 bags to hold the dry ginseng. 2 of the bags will hold 1lb of dried ginseng leaves. so without the stems attached for small to medium size tops the average is about 2000 plants. The stems will probably weigh about 2 times more than the leaves so that would be about 3lbs if the stems were attached. with that being said then if you picked stems and leaves of small to medium size plants i estimate that it would take 650-700 plants to make a pound.
If you are digging larger 4 prong ginseng it will probably only take half of that about 325-350 plants, so in theory if you dig large ginseng then by saving the tops and stems you will probably be able to make an extra $50 per puond.