Yes, we use milk in only one of our products, the Rose Milk, but you have the option to drink it with water :)
Aam Panna is roughly translated to "Mango Tangy Drink" and it tastes tangy, but also, sweet and spicy! Indians loves to taste multiple flavors in one item.
The ingredients required to make the drink are not found at a regular grocery store like Walmart. They come from a special Indian Grocery store who have these shipped from India, which is why they are expensive. In order to ensure no loss to the business, the prices might look high.