Thank you ☺

The weight limit for Media Mail is 70lbs. So if you can get more than one book in a box and keep the weight under 70lbs, Media Mail is the cheapest option. When I get orders of more than 1 book, I tend to do one of the USPS flat rate boxes as, frankly, it’s just easier than finding a custom box that will fit the number of books ordered. They’re pretty reasonably priced.