While most broth and stock recipes call for Marrow Bones you can normally use Knuckle Bones at only a fraction of the cost. Knuckle bones have lots of marrow in them with the added benefit of collagen.
Our family seldom uses actual marrow bones for beef stock. We use either soup bones or knuckle bones and the results are just as good or maybe even better because of the collagen improving joint health.
Each package has 2 knuckles per bag and is about 2-3 lb. total.
Note: we also have Pork Bones available for soup stock.
Here is a great article and recipe for making pork stock: Pork Broth: The Delicious Stock You’ve Probably Never Tried.