Shipping is a flat $24 per order, whatever is in it, and insurance for the full declared value is included in that price. A cart with four cards and a squat rack still pays $24 once.
Cards travel in a rigid holder inside a rigid box. Every order requires a signature, so nothing is left on a porch.
On an international order, import duty and VAT are separate: the destination country charges them to the recipient and they are not part of the $24 or of the checkout total.