Mabinogi World Wiki is your best friend:
http://wiki.mabinogiworld.com/view/Rebirth. Cx
I don't know how much the Beginner services have revamped since I left, but if I recall, you can rebirth daily & reset your skills until a certain total level at no cost of character card through NX required to rebirth.
Limited edition character cards only give you the outfit (and other things if applicable) instead of your default rebirth clothes. Yes, the card disappears.
If you're only after the costume, I'd recommend waiting for the market price on the costume you want to drop lower then to buy the costume with in-game currency rather than NX when it becomes affordable for you.
Something to consider is that since you're also after a Rebirth to change your talent/class if you're over the specified beginner total level, is possible to buy a regular character card and save yourself a bit of NX then use the NX to buy something you can sell in-game for the money you need to obtain your desired costume. An alternative is to wait for a free rebirth at Age 20 if your character is close to that age if you seek then only the rebirth. (1 week per age up every Saturday)
Though if you're willing to pay for both at the same time, it's more convenient, so go for it if you wish. Pay for convenience, I suppose.
[Image: http://media.tumblr.com/tumblr_m9gcwaXdHx1qzckow.gif]