Good news Jazz, you really don't need a credit card, i buy Gamecards, which contain a 2 month subscription they cost around $33.
everquest, Star wars Galaxies, WoW, CoH all make game cards.
You can find tham at most Game stores, or they can order them for you.
The game cards contain a code that you type in in your account section of the game. its as easy as that so $33 bucks for 2 months really isnt bad, even for a broke S.O.B like myself