I know it isn't what you're asking for but even without a credit card you can manage to pay for transfers.
I myself am very skeptical inputting my CC info into anything on the internet out of fear of getting my identity stolen. For that reason, I go to the local supermarket (Stop & Shop where I live) and buy Prepaid Visa Gift Cards. With them, you can put any amount of money you want on them and then after registering it online you can use it for a transfer.
If you aren't interested in this, just ignore me