If it's a prepaid priority mailer than you just pay the base cost depending on the size of the box. Then anything that fits in the box is under that price. If you're using your own boxes than you need to have it sized, weighed and then they can tell you how much depending on speed you need to get it there, insurance, confirmation and other things. I'd recommend you take the items there to get exact quote.
You would need to come in and have it weighed.
Thanks! Your answer is awaiting moderation.