Approximate cost/serving: We grow our own kale and peas which greatly cuts the cost. You can also get them along with mini peppers and Adams Peanut Butter in bulk at Costco. This ended up costing us just $2.40 so about 60 cents per serving.
Vegetarian/Gluten Free: Yes to both, just make sure to go with a gluten free soy sauce. Also vegan and dairy free.