Grand Theft Auto Online Answers for Playstation 3

Is buying a shark card for online worth it?

To be fair, getting money in Gta online is hard. Whenever I try to do a job, such as a heist, there's that one guy who fails the heist in 3 minutes, or when I try a PVP match, there's a dude who is just God and rockets everybody. And racing, Is it not obvious what's gonna happen? So, should I buy a shark card?