I want to play Mabinogi, but i've heard a lot of comments saying Mabinogi sucks the money out of people. So, the question is, do you have to fork out tons of money on the cash shop just to be something in this game?

I don't want over powered cash shop items, people who don't pay, fail, people who do, pwn the people who don't in terms of everything. Is Mabinogi like that?

Well, kinda. If you want to max out your stats and make your character the best he/she can be, you have to pay money to Rebirth.