Well, it helps to read the feedback BEFORE BiDDING.
Er? What Paypal fees? As a buyer you don't pay any and when a seller refunds, his fees are returned.
You may be thinking of foreign exchange differences, but those could work in your favour as well as against you.
You can Report these sellers to eBay. One complaint won't lead to any action, any one can make a mistake, but several will lead to sanctions, including loss of TRS status and removal of selling privileges.