Playstation 3 credit card?

May be...

i live in mexico so can i use a mexican credit card on psn store?

Yes as your Credit Card will be using the Mexican Currency

just go to rite aid and get a prepaid debit card what this is its like a credit card but you add money to it yourself and you can't spend more than you add you also don't get a monthly bill and you can also use the card whenever you want as long as you add money to it so that would be best especialy for buying games from psn you can also pay bills online and make instore and online purchases

yes you can. the prices will most likely still be in dollars but im not sure