How much will it cost to purchase the herbs, ingredients and reference books needed to complete The Science & Art of Herbalism course?

It truly depends on how much of each item you purchase, how many herb books you decide to buy, etc. The minimum cost of supplies needed to complete the 10 lessons is approximately $150 for the necessary herbs and materials to complete the projects in each lesson (making tinctures, salves, creams, oils, syrups). If someone is thrifty and knows how to save, and/or grows their own herbs, uses recycled containers, etc., the cost could be less. If you already have a collection of good herbal books on your shelves, you are welcome to use the reference books you already have and, similarly, you may find that you already have a good number of the herbs on hand as well (e.g. dried Chamomile).