Paypal has a new policy, and it's kind of terrible. Any order that has been cancelled or changed - they get to keep all the fees associated with it. It's about 3.25%.
Read about it here..

If you are cancelling an order for any reason including a double order, changed your mind, wrong items ordered, it's at our discretion to refund or not refund the fees that have been paid to paypal on that order.

Please order carefully.