What do you mean could increase fees? The fees are fix and its does not matter if you use one card of lots of cards as the exchange rate and the value is the same. I been using paypal for many years now and even have an exchange ecurrency site few years ago until my sites and my processors accounts like LR, Alertpay, skrill and paypal has been hacked. But until now the fees is the same regardless of cards I use.As long as your card is your card that is not even matter, you can link more than one from different provider too if you can afford that much, there are a lot of poeple that did the same thing, but remember that using that way could increase the fees.