many  customers ask us why he pay with credit card , the final total cost is more than the website . 
about this question . some RWI member has explain in the forum . because the payment is the oversea payment . 
if the sender bank to our payment access bank need the middle bank to transfer the money , there will be some transfer fee . different bank , the fee different , about 3%-5% . if your currency is not USD , may be there will be exchange rate fee from your bank . so . the extra fee , not all the card will be created!!
normally , if your order over 300$ , we advise you choose western union  , money gram or bank wire . it is cheaper than credit card