We adjust the shipping and/or discounts BEFORE WE CHARGE YOUR CARD. Shipping rate at checkout may not reflect the actual shipping cost. We will refund any overage in once your order has been boxed and weighed. Unfortunately the system doesn't calculate the box size needed to ship your order. USPS & FedEx calculate fee on the size of the box used. The bigger the box, the more room it takes up on their truck. And they charge dearly for it! We don't profit from shipping fees. The amount on your PayPal payment screen or credit card is an authorized amount. Our system authorizes the total amount indicated on your order. We adjust the shipping and/or discounts BEFORE WE CHARGE YOUR CARD.